Glass inner lid *on* water surface???

[T i m]

Hi All,

My daughter decided recently that is wasn't fair for 'Dad' to have to
maintain her 10G tank and the fish would probably be better in a
bigger tank.

So, last night we took the fish (2 clown loaches, 2 pink (/) catfish
and one 'flying Fox (probably?) round to my mates.

Whilst floating the bags etc I noticed the water level was up to the
bottom of the glass inner lids (so that there was NO air gap / contact
between the water and the outside world) and I asked him if that was
'right' (I'm no fish expert or chemist) ;-(

He suggested that the plants (auto fed with Co2 from pressure bottle)
would provide all the oxygen the fish needed (he wasn't adamant, just
suggested that was how it worked ..)?

Now I have Google'd and read some of the Co2 threads on this list so I
think have a rough idea how it should all work .. am I close with
(simply) ..

The ability of the water to support levels of Co2 and O are not
interlinked?

To maintain Co2, minimum surface disturbance is required (so no
airstones etc).

Deep water circulation is good to bring low O water to the surface.

*** The water surface would need access to the 'fresh air' for O to be
absorbed into the water? ***

It's that last bit that has me worried .. ie we take 5 very healthy,
happy and fast growing fish (presumably reflecting good conditions in
my daughters tank) and put them in a nice, big, reasonably planted
tank where they could suffocate?

Thoughts please ... do I need to phone him urgently ..?

All the best ..

T i m (London, UK)

p.s. He has got two phase / level lighting, electronic ph monitoring
(it was 6.45 last night), makes his own 'special' water ? (takes ages)
for regular changes and has external power filters. The fish are
mainly clown loaches, sucking loaches, red faced tetra, one medium
angel and a couple of others).

[NetMax]

"T i m" > wrote in message
...
> Hi All,
>
> My daughter decided recently that is wasn't fair for 'Dad' to have to
> maintain her 10G tank and the fish would probably be better in a
> bigger tank.
>
> So, last night we took the fish (2 clown loaches, 2 pink (/) catfish
> and one 'flying Fox (probably?) round to my mates.
>
> Whilst floating the bags etc I noticed the water level was up to the
> bottom of the glass inner lids (so that there was NO air gap / contact
> between the water and the outside world) and I asked him if that was
> 'right' (I'm no fish expert or chemist) ;-(
>
> He suggested that the plants (auto fed with Co2 from pressure bottle)
> would provide all the oxygen the fish needed (he wasn't adamant, just
> suggested that was how it worked ..)?
>
> Now I have Google'd and read some of the Co2 threads on this list so I
> think have a rough idea how it should all work .. am I close with
> (simply) ..
>
> The ability of the water to support levels of Co2 and O are not
> interlinked?
>
> To maintain Co2, minimum surface disturbance is required (so no
> airstones etc).
>
> Deep water circulation is good to bring low O water to the surface.
>
> *** The water surface would need access to the 'fresh air' for O to be
> absorbed into the water? ***
>
> It's that last bit that has me worried .. ie we take 5 very healthy,
> happy and fast growing fish (presumably reflecting good conditions in
> my daughters tank) and put them in a nice, big, reasonably planted
> tank where they could suffocate?
>
> Thoughts please ... do I need to phone him urgently ..?
>
> All the best ..
>
> T i m (London, UK)
>
> p.s. He has got two phase / level lighting, electronic ph monitoring
> (it was 6.45 last night), makes his own 'special' water ? (takes ages)
> for regular changes and has external power filters. The fish are
> mainly clown loaches, sucking loaches, red faced tetra, one medium
> angel and a couple of others).



Putting the glass cover *on* the water effectively reduces the size of
the tank (from the perspective of re-oxygenation) and depending on the
amount of fish, can be dangerous. Think about night-time, when there are
3 sources of CO2 (DIY, plants & fish) and the only source of O2 is
restricted.

The water/air boundary acts as a buffer, exhausting and taking in gases
to maintain a balance. It will act to make the CO2 system more efficient
(holding in the CO2 longer) because the CO2 is out of balance
(intentionally boosted), but it will restrict balancing of other gases as
well. How important this is will vary by the particulars of the tank
(ie: fish-load, water temperature etc). It may not be a running problem,
but if there is a power failure, pull that cover off!
--
www.NetMax.tk

[Derek W. Benson]

On Sat, 03 Sep 2005 20:50:19 GMT, T i m > wrote:

>Hi All,
>
>My daughter decided recently that is wasn't fair for 'Dad' to have to
>maintain her 10G tank and the fish would probably be better in a
>bigger tank.
>
>So, last night we took the fish (2 clown loaches, 2 pink (/) catfish
>and one 'flying Fox (probably?) round to my mates.
>
>Whilst floating the bags etc I noticed the water level was up to the
>bottom of the glass inner lids (so that there was NO air gap / contact
>between the water and the outside world) and I asked him if that was
>'right' (I'm no fish expert or chemist) ;-(
>

>*** The water surface would need access to the 'fresh air' for O to be
>absorbed into the water? ***
>
>It's that last bit that has me worried .. ie we take 5 very healthy,
>happy and fast growing fish (presumably reflecting good conditions in
>my daughters tank) and put them in a nice, big, reasonably planted
>tank where they could suffocate?
>
>Thoughts please ... do I need to phone him urgently ..?
>All the best ..
>T i m (London, UK)

I think your friend is asking for disaster. You should call him and
INSIST that the water in the tank is not supposed to be up to the
glass covering. There is supposed to be air in there because of the
exchange of gases at the surface as NetMax eloquently described.

-Derek

[T i m]

On Sat, 3 Sep 2005 21:56:10 -0400, "NetMax"
> wrote:


>> Whilst floating the bags etc I noticed the water level was up to the
>> bottom of the glass inner lids (so that there was NO air gap / contact
>> between the water and the outside world) and I asked him if that was
>> 'right' (I'm no fish expert or chemist) ;-(


>Putting the glass cover *on* the water effectively reduces the size of
>the tank (from the perspective of re-oxygenation) and depending on the
>amount of fish, can be dangerous. Think about night-time, when there are
>3 sources of CO2 (DIY, plants & fish) and the only source of O2 is
>restricted.

Ok ..
>
>The water/air boundary acts as a buffer, exhausting and taking in gases
>to maintain a balance. It will act to make the CO2 system more efficient
>(holding in the CO2 longer) because the CO2 is out of balance
>(intentionally boosted), but it will restrict balancing of other gases as
>well.

Understood (thanks for putting it so clearly) ;-)

How important this is will vary by the particulars of the tank
>(ie: fish-load, water temperature etc). It may not be a running problem,
>but if there is a power failure, pull that cover off!

Ok, so, may I ask a for confirmation ... for yer ordinary guy in the
street, (reasonable loading, easy community fish etc) having a glass
inner lid with no air gap above the water is *not* generally
considered to be a 'good thing' please?

The reason I would like to be clear re the facts 'in practice' is that
I may (gently) suggest to my mate (and he's a good mate so I can't see
any real issues here) that there may be 'better' ways of setiing his
tank re this point ..? I mean could he also provide overwhelming
evidence that his way is the better way or does the basic chemistry of
it all (as you outlined above) say it all?

All the best and thanks very much for your time and info ..

T i m

p.s. His flat can get quite warm, even to a point where he was
considering some way of force cooling the tank .. do I understand it
could make the above issue worse?

[T i m]

On Sun, 04 Sep 2005 11:57:11 +0200, Derek W. Benson >
wrote:


>>Whilst floating the bags etc I noticed the water level was up to the
>>bottom of the glass inner lids (so that there was NO air gap / contact
>>between the water and the outside world) and I asked him if that was
>>'right' (I'm no fish expert or chemist) ;-(
>>
>
>I think your friend is asking for disaster. You should call him and
>INSIST that the water in the tank is not supposed to be up to the
>glass covering. There is supposed to be air in there because of the
>exchange of gases at the surface as NetMax eloquently described.

Hi Derek,

Oh, so it really is as bad as I feared? ;-(

I suppose I was hoping that it was *ok* so that there wasn't any risk
to the fish we had fairly carefully looked after for the last couple
of years .. ;-(

One easy 'get out clause' I thought we might have had is *maybe* the
addition of the two small bags of water we took the fish in may have
taken the water level over the (his) norm and he would have normally
had the gap. I fear there wasn't enough water to make that sorta
diffence in that size tank though? <sigh> ;-(

Just so I know whatt we are aming for, what sort of gap would be
'ideal' and do we also assume there should be some air-gaps around the
glass somewhere to allow 'fresh' air into the gaps (do I remember
seeing corners missing on these sliding lids etc?)

All the best and thank you very much for your time / advice .. (from
me and the fish!) ;-)

T i m
p.s. I just phoned him and caught him at home (made an excuse for
another question). I put across my thoughts and how (so far) there
have been two replies supporting them, he seemed to hear what I had to
say but suggested 'that's how it's been for a while and it seems to
work'?

Now I know him fairly well and there's a possibility he may consider
what I (via you guys <g>) have said and lower the level a bit (he may
even tell me he has done so) but it would be a real shame if say the
extra 5 fish take the stocking level past what *his* system can cope
with and fish die ... ;-(

All the best ..

T i m

p.s. Is it possible this practice was *in* at some time and that's why
he thinks this way?

[NetMax]

"T i m" > wrote in message
...
> On Sat, 3 Sep 2005 21:56:10 -0400, "NetMax"
> > wrote:
>
>
>>> Whilst floating the bags etc I noticed the water level was up to the
>>> bottom of the glass inner lids (so that there was NO air gap /
>>> contact
>>> between the water and the outside world) and I asked him if that was
>>> 'right' (I'm no fish expert or chemist) ;-(
>
>
>>Putting the glass cover *on* the water effectively reduces the size of
>>the tank (from the perspective of re-oxygenation) and depending on the
>>amount of fish, can be dangerous. Think about night-time, when there
>>are
>>3 sources of CO2 (DIY, plants & fish) and the only source of O2 is
>>restricted.
>
> Ok ..
>>
>>The water/air boundary acts as a buffer, exhausting and taking in gases
>>to maintain a balance. It will act to make the CO2 system more
>>efficient
>>(holding in the CO2 longer) because the CO2 is out of balance
>>(intentionally boosted), but it will restrict balancing of other gases
>>as
>>well.
>
> Understood (thanks for putting it so clearly) ;-)
>
> How important this is will vary by the particulars of the tank
>>(ie: fish-load, water temperature etc). It may not be a running
>>problem,
>>but if there is a power failure, pull that cover off!
>
> Ok, so, may I ask a for confirmation ... for yer ordinary guy in the
> street, (reasonable loading, easy community fish etc) having a glass
> inner lid with no air gap above the water is *not* generally
> considered to be a 'good thing' please?

Correct, not a good thing. Many books use the example of the fish in a
fishbowl to demonstrate this. Fill the bowl to the top where the vessel
narrows and the fish is clearly under stress, gasping at the surface.
Only fill half the bowl and the fish is fine.

Or put in another way, fish will always consume ALL the O2 in an aquarium
(the bigger the tank the longer it takes), and the air contact (surface
area, turbulence etc) determines the rate at which O2 can get back in.

> The reason I would like to be clear re the facts 'in practice' is that
> I may (gently) suggest to my mate (and he's a good mate so I can't see
> any real issues here) that there may be 'better' ways of setiing his
> tank re this point ..? I mean could he also provide overwhelming
> evidence that his way is the better way or does the basic chemistry of
> it all (as you outlined above) say it all?

It is basic stuff. He could tell you that he has a sump filter (which
does a very good gas exchange), and then he would have a better argument
for leaving it like this (the flaw remains the effects of a power
failure). There really is no reason to do this, except as already noted,
to help maintain an imbalance of gases (higher CO2 concentration for the
amount being added, so the plants grow better).

> All the best and thanks very much for your time and info ..
>
> T i m
>
> p.s. His flat can get quite warm, even to a point where he was
> considering some way of force cooling the tank .. do I understand it
> could make the above issue worse?

One of the ways water cools is by evaporation, so the glass cover
prevents that. The glass is also acting as an insulator, so overall, not
a good idea.

He only needs the smallest of gaps between the water and the glass
(enough to jostle a few billion molecules back & forth ;~).

I think your bags of water brought the level up and in a few days, it
will drop back down. Mention to him that the only source of oxygen to
the fish is through contact area to air, and it would be better to keep
the glass out of the water. hth
--
www.NetMax.tk

[T i m]

On Sun, 4 Sep 2005 08:13:50 -0400, "NetMax"
> wrote:


>> Ok, so, may I ask a for confirmation ... for yer ordinary guy in the
>> street, (reasonable loading, easy community fish etc) having a glass
>> inner lid with no air gap above the water is *not* generally
>> considered to be a 'good thing' please?
>
>Correct, not a good thing. Many books use the example of the fish in a
>fishbowl to demonstrate this. Fill the bowl to the top where the vessel
>narrows and the fish is clearly under stress, gasping at the surface.
>Only fill half the bowl and the fish is fine.

Understood. Not wanting to overcomplicate that example but if the bowl
contained plants and was filled to the brim and there was enough O2 to
last all night .. we should still be ok .. (not not ideal)?
>
>Or put in another way, fish will always consume ALL the O2 in an aquarium
>(the bigger the tank the longer it takes), and the air contact (surface
>area, turbulence etc) determines the rate at which O2 can get back in.

Ah, ok .. another good perspective. Ta.
>

<snip> He could tell you that he has a sump filter (which
>does a very good gas exchange), and then he would have a better argument
>for leaving it like this (the flaw remains the effects of a power
>failure).

Well, from the telephone chat we had this morning he reminded me he
had two external power filters, one 'biological' and the other
'physical'? Would either of these be 'sump filters' please?

>> p.s. His flat can get quite warm, even to a point where he was
>> considering some way of force cooling the tank .. do I understand it
>> could make the above issue worse?
>
>One of the ways water cools is by evaporation, so the glass cover
>prevents that. The glass is also acting as an insulator, so overall, not
>a good idea.

So that's two cons and no pro's by my count (O2 and heat)?

>He only needs the smallest of gaps between the water and the glass
>(enough to jostle a few billion molecules back & forth ;~).

Ok, so that might be a compromise (tiny rather than no gap) .. maybe I
could sneak in and nick a few pints of water!
>
>I think your bags of water brought the level up and in a few days, it
>will drop back down. Mention to him that the only source of oxygen to
>the fish is through contact area to air, and it would be better to keep
>the glass out of the water.

I'll run it past him again when I see him on Monday ... but he can be
a bit stubborn. Would the existance of the 'sump filter' completely
negate the issues re the above (excluding power cuts) NetMaX or is
this an 'as well' concept please?

Sorry for all the questions .. I need all the answers to be able to
cover all the bases with him .. ;-)

All the best and thanks again ..

T i m

[NetMax]

"T i m" > wrote in message
...
> On Sun, 4 Sep 2005 08:13:50 -0400, "NetMax"
> > wrote:
>
>
>>> Ok, so, may I ask a for confirmation ... for yer ordinary guy in the
>>> street, (reasonable loading, easy community fish etc) having a glass
>>> inner lid with no air gap above the water is *not* generally
>>> considered to be a 'good thing' please?
>>
>>Correct, not a good thing. Many books use the example of the fish in a
>>fishbowl to demonstrate this. Fill the bowl to the top where the
>>vessel
>>narrows and the fish is clearly under stress, gasping at the surface.
>>Only fill half the bowl and the fish is fine.
>
> Understood. Not wanting to overcomplicate that example but if the bowl
> contained plants and was filled to the brim and there was enough O2 to
> last all night .. we should still be ok .. (not not ideal)?

If the bowl had no plants, then the fish will do better. At night,
plants are also using up the O2. Plants only give O2 back when
photosynthesizing (under light conditions).

>>Or put in another way, fish will always consume ALL the O2 in an
>>aquarium
>>(the bigger the tank the longer it takes), and the air contact (surface
>>area, turbulence etc) determines the rate at which O2 can get back in.
>
> Ah, ok .. another good perspective. Ta.
>>
>
> <snip> He could tell you that he has a sump filter (which
>>does a very good gas exchange), and then he would have a better
>>argument
>>for leaving it like this (the flaw remains the effects of a power
>>failure).
>
> Well, from the telephone chat we had this morning he reminded me he
> had two external power filters, one 'biological' and the other
> 'physical'? Would either of these be 'sump filters' please?

Not likely. An external canister filter does nothing for gaseous
exchanges because it is a closed loop (no air contact). An external
powerfilter would help considerably, but only across the surface exposed
to air. A sump filter is like a small aquarium under the tank, and water
trickles into plates before collecting at the bottom and being pumped
back up.

>>> p.s. His flat can get quite warm, even to a point where he was
>>> considering some way of force cooling the tank .. do I understand it
>>> could make the above issue worse?
>>
>>One of the ways water cools is by evaporation, so the glass cover
>>prevents that. The glass is also acting as an insulator, so overall,
>>not
>>a good idea.
>
> So that's two cons and no pro's by my count (O2 and heat)?
>
>>He only needs the smallest of gaps between the water and the glass
>>(enough to jostle a few billion molecules back & forth ;~).
>
> Ok, so that might be a compromise (tiny rather than no gap) .. maybe I
> could sneak in and nick a few pints of water!

lol

>>I think your bags of water brought the level up and in a few days, it
>>will drop back down. Mention to him that the only source of oxygen to
>>the fish is through contact area to air, and it would be better to keep
>>the glass out of the water.
>
> I'll run it past him again when I see him on Monday ... but he can be
> a bit stubborn. Would the existance of the 'sump filter' completely
> negate the issues re the above (excluding power cuts) NetMaX or is
> this an 'as well' concept please?

I think it would depend on the flow rate and the fish-load.

> Sorry for all the questions .. I need all the answers to be able to
> cover all the bases with him .. ;-)
>
> All the best and thanks again ..
>
> T i m

Another way to look at this is that water holds much less O2 than air (I
forget the %), so fish have become very specialized to make the best of
every bit of O2 they can find. Many catfish (cory, pleco)'s intestinal
lining can absorb O2. Betta, gouramis and other anabantidae can mouth
air and remove the O2 through a labyrinth organ. Unfolded, the gill
membranes of a fish can be longer than the fish. Anything you can do to
keep the O2 level higher (towards that already very low maximum soluble
in water) will give you healthier and more active fish.

If that doesn't convince him, then point out that the fish are all going
to break their jaws rushing to the surface and smacking into a piece of
glass everytime they are going for food or a gulp of air ;~). Fish do
figure this out, but if the glass is very close, they will smack
themselves, so it's good to leave a small gap, like 1/2".
--
www.NetMax.tk

[T i m]

On Sun, 4 Sep 2005 16:26:51 -0400, "NetMax"
> wrote:

<snip>
>> Understood. Not wanting to overcomplicate that example but if the bowl
>> contained plants and was filled to the brim and there was enough O2 to
>> last all night .. we should still be ok .. (not not ideal)?
>
>If the bowl had no plants, then the fish will do better. At night,
>plants are also using up the O2. Plants only give O2 back when
>photosynthesizing (under light conditions).

So with typical lighting would the O2 be net positive or just neutral
in the above (in throry, no real data I know). Ie, are the plants worh
having O2 wize?
>

<snip>
>A sump filter is like a small aquarium under the tank, and water
>trickles into plates before collecting at the bottom and being pumped
>back up.

Ah, I'm pretty sure he's not got one of them then ;-(
>
>
>Another way to look at this is that water holds much less O2 than air (I
>forget the %), so fish have become very specialized to make the best of
>every bit of O2 they can find. Many catfish (cory, pleco)'s intestinal
>lining can absorb O2. Betta, gouramis and other anabantidae can mouth
>air and remove the O2 through a labyrinth organ. Unfolded, the gill
>membranes of a fish can be longer than the fish.

Wow .. interesting stuff! ;-)

Anything you can do to
>keep the O2 level higher (towards that already very low maximum soluble
>in water) will give you healthier and more active fish.

Understood
>
>If that doesn't convince him, then point out that the fish are all going
>to break their jaws rushing to the surface and smacking into a piece of
>glass everytime they are going for food or a gulp of air ;~).

Well Ib didn't mention this before because it sorta was low importance
but I was watching them whilst they were settling in and that was
bothering me.

My daughter had two two pink looking catfish (I Googled about and they
could be "Pink Aeneus Corydoras" except their eyes are the same colour
as their bodies and they act as if they are blind?). These generally
just swam about near the bottom but quite regularly would shoot up to
the surface and (I assume) even come out of it slightly, coming back
down in a plume of bubbles? While watching them in thir new bigger
surroundings it was quite painfull to see them banging their heads on
the 'glass ceiling'? <sigh>.

Fish do
>figure this out, but if the glass is very close, they will smack
>themselves, so it's good to leave a small gap, like 1/2".

How do I get him to change something he obviously believes it the
right thing to do .. I mean had I realised it was this way *before* I
(we) gave him the fish I don't think I would have (I have another mate
with a big community tank who would have had them and his has that
corrugated type of inner lid but it''s well clear of the surface ..) ?

It's not going to be easy to get them back now ... ;-(

All the best, and thank VERY much for all your time / care re this
NetMax ;-)

T i m

[NetMax]

"T i m" > wrote in message
...
> On Sun, 4 Sep 2005 16:26:51 -0400, "NetMax"
> > wrote:
>
> <snip>
> So with typical lighting would the O2 be net positive or just neutral
> in the above (in throry, no real data I know). Ie, are the plants worh
> having O2 wize?

I suspect that they are net O2 positive, and besides the O2, they are
very good filters.

> <snip>
> All the best, and thank VERY much for all your time / care re this
> NetMax ;-)
>
> T i m

You're very welcome : ), good luck !
--
www.NetMax.tk

[T i m]

On Sun, 4 Sep 2005 22:03:56 -0400, "NetMax"
> wrote:



>> All the best, and thank VERY much for all your time / care re this
>> NetMax ;-)
>>
>> T i m
>
>You're very welcome : ), good luck !

Thanks again .. I *hope* he will understand .. I'll let you know the
outcome ..

All the best ..

T i m

[Derek W. Benson]

On Sun, 04 Sep 2005 10:54:15 GMT, T i m > wrote:

>Hi Derek,
>
>Oh, so it really is as bad as I feared? ;-(
>
>I suppose I was hoping that it was *ok* so that there wasn't any risk
>to the fish we had fairly carefully looked after for the last couple
>of years .. ;-(
>
>One easy 'get out clause' I thought we might have had is *maybe* the
>addition of the two small bags of water we took the fish in may have
>taken the water level over the (his) norm and he would have normally
>had the gap. I fear there wasn't enough water to make that sorta
>diffence in that size tank though? <sigh> ;-(
>
>Just so I know whatt we are aming for, what sort of gap would be
>'ideal' and do we also assume there should be some air-gaps around the
>glass somewhere to allow 'fresh' air into the gaps (do I remember
>seeing corners missing on these sliding lids etc?)
>
>All the best and thank you very much for your time / advice .. (from
>me and the fish!) ;-)
>
>T i m
>p.s. I just phoned him and caught him at home (made an excuse for
>another question). I put across my thoughts and how (so far) there
>have been two replies supporting them, he seemed to hear what I had to
>say but suggested 'that's how it's been for a while and it seems to
>work'?
>
>Now I know him fairly well and there's a possibility he may consider
>what I (via you guys <g>) have said and lower the level a bit (he may
>even tell me he has done so) but it would be a real shame if say the
>extra 5 fish take the stocking level past what *his* system can cope
>with and fish die ... ;-(
>
>All the best ..
>
>T i m
>
>p.s. Is it possible this practice was *in* at some time and that's why
>he thinks this way?

The vast majority of home aquariums I've ever seen have a frame around
them, also at the top. All-glass aquariums will also usually have a
frame around the top. The water should be filled up to the bottom edge
of this frame, so all you see when you're looking at the tank is
water. The air at the top is blocked from view by the frame. So
usually you will have about 1/2 inch or maybe a bit more of air above
the water. What the "ideal" amount of air between the water and glass
top is, is impossible for me to say. A half inch is certainly enough.
The glass top on the tank probably has a corner or two cut away; this
is for putting in filter hoses, heater, etc.

I don't think his practice was ever "in"; I've never seen or heard of
anyone filling up their tank all the way to the top glass in 40 years
of keeping and looking at aquariums.

-Derek

[T i m]

On Mon, 05 Sep 2005 21:24:16 +0200, Derek W. Benson >
wrote:


>>p.s. Is it possible this practice was *in* at some time and that's why
>>he thinks this way?
>
>The vast majority of home aquariums I've ever seen have a frame around
>them, also at the top. All-glass aquariums will also usually have a
>frame around the top.

Yup ..

The water should be filled up to the bottom edge
>of this frame, so all you see when you're looking at the tank is
>water. The air at the top is blocked from view by the frame.

That's how we used to keeep my Daughters tank (and all the ones I had
in the past) ;-)

So
>usually you will have about 1/2 inch or maybe a bit more of air above
>the water.

On her last tank you got about 3/4" to the top of the frame then quite
a bit more in and around around the lid (no glass 'inner' lid)

What the "ideal" amount of air between the water and glass
>top is, is impossible for me to say. A half inch is certainly enough.

I think NetMax suggested the absolute minimum being a few molecules
but I would be happy if my mate had *anything* ;-)

>The glass top on the tank probably has a corner or two cut away; this
>is for putting in filter hoses, heater, etc.

I didn't actually see the back because only the front half of the
outer lid was folded back .. I imagine there must have been 'gaps /
corners' as he has various power filters etc.
>
>I don't think his practice was ever "in"; I've never seen or heard of
>anyone filling up their tank all the way to the top glass in 40 years
>of keeping and looking at aquariums.

That is the sort of feedback I'm looking for Derek (and from the
previous posts the chemistry re *why* it's not seen)?

I did spent a bit of time with my mate today but there wasn't a
suitable 'moment' to bring up the subject. I even feel he's the type
that even if I printed off the various replies in this thread and
showed them to him he would still stick by 'his ways' (he CAN be
stubborn). But he must have got this notion from somewhere?

If I catch him on his own tomorrow and he seems in a suitable mood I
might try to bring up the subject again. I think it's like talking to
drunks though .. *they* think they are sober .. ;-(

All the best and thanks very much again Derek ..

T i m

[T i m]

Hi All,

Re the ongoing issue with the mate that took the last of my daughters
fish .. the one with the water right up to underside of the glass (no
air gap).

I managed to catch him in a better mood yesterday (he's actually not
very well .. long term problems) and he raided the tropical fish
subject so I chanced my arm again ;-)

Basically, it seems the 'reason' he keeps the water tight under the
inner glass lid is because he thinks he read such instructions with
his Co2 injector kit?

He did say he tested the o2 levels using a chemical kit and they were
always 'ok' (but added sutff about charts, PC progs and CO2 probes and
graphs not 'matching up' ?) <shrug>.

He seems to think that he *needs* CO2 injection (during the day) to
grow plants ... my daughter and I were always pruning our plants back
and we had no CO2 system?

I tried to offer him the bottom line and he even eluded to the fact
himself and that was "the tank surface area determines the fish
stocking levels .."

I mentioned that his tank surface area was zero?

He said my daughters 5 fish (2 x catfish, 2 x clown loaches, 1 x
siamese algae eater) are still allive and healthy ..?

I'll keep working on him though ... ;-)

All the best ..

T i m

p.s. He said he was due to do a ''complete tank stripdown" soon but it
was expensive because he had to change all the gravel (does it every 2
years) .. is this needed or something else he has imagined must be
done? (I argued that the gravel had been around for a few million
years so a couple of years in his tank wouldn't make much difference
....?). He said I would take it all out, give it a good wash (bleach it
to kill any creatures) rinse it VERY well and put it back? He said he
would never bleach anything that was to go in a tank?

[Tynk]

T i m Wrote>>

p.s. He said he was due to do a ''complete tank stripdown" soon but it
was expensive because he had to change all the gravel (does it every 2
years) .. is this needed or something else he has imagined must be
done? (I argued that the gravel had been around for a few million
years so a couple of years in his tank wouldn't make much difference
....?). He said I would take it all out, give it a good wash (bleach it
to kill any creatures) rinse it VERY well and put it back? He said he
would never bleach anything that was to go in a tank?

Wow.
There no valid reason for tearing down a tank every couple of years.
Why on earth would he replace the gravel as well.
I didn't understand the bleaching sentence, it was a little confusing.
Do you bleach gravel, clean it and then re-use it, or was he suggesting
that that was not right to do, or what?
And the fact that he wouldn't bleach anything that goes in his tank is
goofy. Sometimes bleach IS the thing to do for certain diseases.
People do some weird things with their tanks, but a total tear down
every couple of years is kind of nuts.
It also destroys the nirifying bacteria and has to re-cycle the tank
every time he does this. Why anyone would do that on purpose when it's
not needed is beyond me.
There is such a syndrome as *old* tank syndrome, but with regular water
changes and monthly gravel vacs it's not going to happen. Only when
poor tank maintenance is done will that be a problem.

[T i m]

On 13 Sep 2005 08:43:15 -0700, "Tynk" > wrote:

>Wow.

Sorry for blurting it all out Tynk ;-)

>There no valid reason for tearing down a tank every couple of years.

Ok .. thanks .. (I never did but I was just trying to ger a 'feel' for
is considered 'normal' these days).

>Why on earth would he replace the gravel as well.

Pass <shrug>

>I didn't understand the bleaching sentence, it was a little confusing.
>Do you bleach gravel, clean it and then re-use it, or was he suggesting
>that that was not right to do, or what?

The latter. I read here re when someone was shutting down a tank to
'clean / bleach all the items / gravel etc' . I suggested that to my
mate and he siad the "I'd never put bleach near my tank etc .." bit?

>And the fact that he wouldn't bleach anything that goes in his tank is
>goofy.

Well, I thought that might be the case after he said what he said ...

Sometimes bleach IS the thing to do for certain diseases.

Understood.

>People do some weird things with their tanks, but a total tear down
>every couple of years is kind of nuts.

Especially one as big as his (guess 4' x 2' x 18")? He also mentioned
that the job was made especially messy as he puts a layer of clay (he
thinks) in the bottom of the tank before the gravel?

>It also destroys the nirifying bacteria and has to re-cycle the tank
>every time he does this. Why anyone would do that on purpose when it's
>not needed is beyond me.

Well, and me and hence I thought I'd ask the experts ;-)

>There is such a syndrome as *old* tank syndrome, but with regular water
>changes and monthly gravel vacs it's not going to happen. Only when
>poor tank maintenance is done will that be a problem.

Understood.

Strange isn't it .. you see a large tank, twin external filters, twin
stage lights, CO2 injection with digital displays of PH etc etc and
come to the conclusion that they know what they are doing?

I have discussed (queeried) some of these points with him but he seems
to think what he is doing is correct? I have kept fish on / off since
I was 10 (now 49) and after talking to him thought I had missed some
new ideas?

I was worried that maybe this info had been given to him by his
departed father or something .. didn't want to offend him by
suggesting outright that his techniques were 'way off' .. ;-(

Not sure where to go from here ... ?

All the best and thanks for your feedback / time ..

T i m (in London)