Overstocked tank - and limits for alkalinity

[Pszemol]

I have heavily overstocked 30 gallons tank with high
pH swings and low pH average (day: 8.1, night 7.6)
I was wondering if there is a way to help things up
a little without removing animals or moving to a bigger
tank... What are the safe upper limits of alkalinity?
Currently my alk is around 10-11'dK and still my pH
swings is low and swings too much. Enough to say I see
shells the hermit crabs live in dissolve in the water
causing my Ca levels to be above 500mg/l...

I was reading about alkalinity that high levels stabilize
pH in the upper levels but I do not see it happen in my tank.
How one can explain chemistry in my tank ?

[Toni]

"Pszemol" > wrote in message
...
>
> I was reading about alkalinity that high levels stabilize
> pH in the upper levels but I do not see it happen in my tank.
> How one can explain chemistry in my tank ?


Perhaps your room has an excess of CO2??
Can you open a window?
Sounds terribly simple but it worked for me.

Here is a must read:
Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm



--
Toni
http://www.cearbhaill.com/reef.htm

[KevinM]

"Pszemol" > wrote in message
...
> No, I like to keep my windows open an air fresh...
> Anyway, high levels of alkalinity buffer should
> compensate for CO2 solving in the water, shouldn't it?


No. You can have high alk, and if you pump CO2 into the water, you will
depress the pH. No amount of alkalinity can stop it. Only with good water
circulation, a clean air/water interface, and low CO2 in the ambient air,
can you lessen the effect.

Try this...take a sample of our water early in the morning before the lights
come on, check the pH, then take it outside and blow air bubbles into it
with a straw to aerate it. Now, check the pH again. If it went up, you have
a CO2 problem. If it stayed the same, I'd check the accuracy of my Alk test.

I thought you were up on your Alk/Ca/CO2 relationships? You slippin'? heheh

Kev

[Pszemol]

"KevinM" > wrote in message . com...
> I thought you were up on your Alk/Ca/CO2 relationships? You slippin'? heheh

I have to refresh what I read more often... I am getting old ;-)

[Pszemol]

"Toni" > wrote in message ...
> Hey-I wouldn't have known except I just went through it.
> I started dripping kalk to get the pH back up into a decent range, and it's
> now cool enough in SoFla that I can leave a window open and a fan on through
> the night.
> I made it all the way up to 8.3 today!!

Great!

I have made the air test today, and "eureka"!
My datalog from measurements in the cup of fish tank water taken outside the window:

pH =7.78 <= this was the morning low
07:34 11-19-04

pH =7.81
07:35 11-19-04

pH =7.82
07:36 11-19-04

pH =7.85
07:37 11-19-04

pH =7.87
07:38 11-19-04

pH =7.89
07:39 11-19-04

pH =7.91
07:40 11-19-04

pH =7.92
07:41 11-19-04

pH =7.94
07:42 11-19-04

pH =7.95
07:43 11-19-04

pH =7.97
07:44 11-19-04

pH =7.97
07:45 11-19-04

pH =7.98
07:46 11-19-04

pH =7.98
07:47 11-19-04

pH =7.99
07:48 11-19-04

pH =7.99
07:49 11-19-04

pH =8.01
07:50 11-19-04

pH =8.02
07:51 11-19-04

pH =8.03
07:52 11-19-04

pH =8.03
07:52 11-19-04

pH =8.13
08:03 11-19-04

pH =8.05
07:53 11-19-04

pH =8.06
07:54 11-19-04

pH =8.06
07:55 11-19-04

pH =8.07
07:56 11-19-04

pH =8.08
07:57 11-19-04

pH =8.09
07:58 11-19-04

pH =8.10
07:59 11-19-04

pH =8.11
08:00 11-19-04

pH =8.11
08:01 11-19-04

pH =8.12
08:02 11-19-04

pH =8.13
08:03 11-19-04

pH =8.13
08:03 11-19-04

pH =8.13
08:04 11-19-04

pH =8.14
08:05 11-19-04

pH =8.14
08:06 11-19-04

pH =8.15
08:07 11-19-04

pH =8.16
08:08 11-19-04

pH =8.16
08:09 11-19-04

pH =8.17
08:10 11-19-04

pH =8.17
08:11 11-19-04

pH =8.17
08:12 11-19-04

pH =8.18
08:13 11-19-04

pH =8.18
08:14 11-19-04

pH =8.19
08:15 11-19-04


pH =8.21
08:25 11-19-04


pH =8.22 <= this is very good!
08:28 11-19-04

The only thing in my experiment which is to be verified is that
the temperature dropped from original 27'C to 15'C (today was quite nice).
How should I correct my reading? I can probably check it myself...

[Pszemol]

"Pszemol" > wrote in message ...
> The only thing in my experiment which is to be verified is that
> the temperature dropped from original 27'C to 15'C (today was quite nice).
> How should I correct my reading? I can probably check it myself...

Ok, my pH-meter has the temperature correction function, so I did
not need to calculate anything - with the measurements of pH 8.24
at 15'C and pH-meter set to 25'C I switched it to 15'c and the
reading jumped to 8.28 right a way. So it looks like the pH is
going way up with the temp going down... Even better for the air test!

[Pszemol]

"KevinM" > wrote in message . com...
> No. You can have high alk, and if you pump CO2 into the water, you will
> depress the pH. No amount of alkalinity can stop it. Only with good water
> circulation, a clean air/water interface, and low CO2 in the ambient air,
> can you lessen the effect.

This is so true... I made 2nd test today - this time indoors...
Guess what - my pH lifted very little, from 7.70 to 7.74 and
did not move a bit more over next 30-40 minutes... Not like
yesterday, when during pumping outside air I maganed to get 8.22
So - I was wrong... my indoor air is not fresh!

I need to hook up my skimmer air intake to the outside air somehow.

[KevinM]

"Pszemol" > wrote in message
...

> I need to hook up my skimmer air intake to the outside air somehow.

Do this and your current pH problem will go away. Just be sure to use
oversized tubing so as not to choke off the air too much.

Kev

[Pszemol]

"KevinM" > wrote in message . com...
>> I need to hook up my skimmer air intake to the outside air somehow.
>
> Do this and your current pH problem will go away. Just be sure to use
> oversized tubing so as not to choke off the air too much.

But what about the tank water surface ? It is agitated right now...
Wouldn't it interfere with what I want to do ? The water surface
will be exchanging pressure with the indoor air full of CO2... :-(

[KevinM]

"Pszemol" > wrote in message
...
> But what about the tank water surface ? It is agitated right now...
> Wouldn't it interfere with what I want to do ? The water surface
> will be exchanging pressure with the indoor air full of CO2... :-(

Most likely not. There is alot more gas exchange going on inside that
skimmer than at your air/water interface. Although I would try to see if I
could get more fresh air in the house, I don't think it will upset your
efforts if you don't. Just hooking your air intake to the outside air will
help some, as it will be constantly pumping fresh air inside.

BTW, what kind of skimmer are you using? What size air inlet on it? (My air
intake is a garden hose)
If your skimmer is, for example, a Skilter (God forbid), I wouldn't expect
much out of it in the way of blowing off CO2. If, on the other hand, you
have something like a AquaC, ER, Beckett, etc...type, something with a
decent sized pump running it, it should have no problem keeping your CO2
blown off.

Kev

[Pszemol]

"KevinM" > wrote in message . com...
> Most likely not. There is alot more gas exchange going on inside that
> skimmer than at your air/water interface. Although I would try to see if I
> could get more fresh air in the house, I don't think it will upset your
> efforts if you don't. Just hooking your air intake to the outside air will
> help some, as it will be constantly pumping fresh air inside.

I hooked up the skimmer to the outside air using the fact my tank
sits near the wall air-condition unit. I run the larger (2x) diameter
tubing near the air condition unit (between the unit and the sleeve)
so the intake is outside, through the "grill" in the unit sleeve box...
Than I link the smaller tubing going into the skimmer and then into my
water column... Unfortunatelly, pH this morning was again low, 7.75 :-(

> BTW, what kind of skimmer are you using? What size air inlet on it?
> (My air intake is a garden hose)
> If your skimmer is, for example, a Skilter (God forbid), I wouldn't expect
> much out of it in the way of blowing off CO2. If, on the other hand, you
> have something like a AquaC, ER, Beckett, etc...type, something with a
> decent sized pump running it, it should have no problem keeping your CO2
> blown off.

I am using small SeaClone 100 - my tank is only 30 gallon of water.
The skimmer is powered with the MaxiJet 1200 with an regular air tube
as its air intake.

Instead of buying jumbo skimmer for $$$ I think I will finally make
a sump for that tank and run a lot of macroalgae with the light period
in the opposit phase to the main tank... That is the only thing I can
think of currently.

[Toni]

"Pszemol" > wrote in message
...
>
> Instead of buying jumbo skimmer for $$$ I think I will finally make
> a sump for that tank and run a lot of macroalgae with the light period
> in the opposit phase to the main tank... That is the only thing I can
> think of currently.



I'm sorry but I don't recall- do you drip kalk?
Doing so overnight will fix that low pH.



--
Toni
http://www.cearbhaill.com/reef.htm

[Pszemol]

"Toni" > wrote in message . ..
>> Instead of buying jumbo skimmer for $$$ I think I will finally make
>> a sump for that tank and run a lot of macroalgae with the light period
>> in the opposit phase to the main tank... That is the only thing I can
>> think of currently.
>
> I'm sorry but I don't recall- do you drip kalk?
> Doing so overnight will fix that low pH.

I do not... Somehow my Ca levels are very high - 500mg/l and above.
Probably from shells/substrate dissolving during low pH phases...
Something similar to what happens in Ca/CO2 reactors maybe.

[Pszemol]

"Toni" > wrote in message . ..
>> Instead of buying jumbo skimmer for $$$ I think I will finally make
>> a sump for that tank and run a lot of macroalgae with the light period
>> in the opposit phase to the main tank... That is the only thing I can
>> think of currently.
>
> I'm sorry but I don't recall- do you drip kalk?
> Doing so overnight will fix that low pH.

Last night I decided to try kalkwasser...
Got one spoon of KENT kalkwasser powder in the gallon of RO/RI watter.
Let it clear up for an hour or two and started dripping to the tank,
just after the lights went out. The dripping rate was preset with
a cheapo plastic air valve, so it was not very accurate, but the drops
were falling into the tank at a rate est. on drop per 5 seconds...
It averaged about 2ml of kalkwasser per minute into my 30-gallons tank.

I let it drip over night - this morning I noticed dripping rate fall
down to about one drop per 10 seconds (valve did not hold the setting)
and pH was higher than the last morning: 7.88 - about 0.10 above
the normal morning reading. Should I expect more rapid results after
dropping kalkwasser or what I saw is normal ?

I stopped dripping before leaving to work this morning - I will start
it again this evening. Should I observe better, accumulated results next
night or what I measured this morning will repeat tomorrow, so to get higher
pH (to about 7.9-8.0) I should increase dripping rate (increase dose) ?

[Toni]

"Pszemol" > wrote in message
...
>
> I stopped dripping before leaving to work this morning - I will start
> it again this evening. Should I observe better, accumulated results next
> night or what I measured this morning will repeat tomorrow, so to get
higher
> pH (to about 7.9-8.0) I should increase dripping rate (increase dose) ?


I have just begun dripping kalk myself, so I am not the most experienced
person around.
I do just repeat the same results every night- in other words my pH never
gets up and stays up- I just try and keep it from lowering too much
overnight. It is just a matter of trial and error to get things right for
your system.

An increased amount of kalk in the water does keep my pH higher overnight- I
believe RO water will hold as much as 2 tsp per gallon. But I am still
experimenting with mixing ratios, drips per second, and hours of dripping.
I know that many people with chronic low pH drip 24/7.

I have a lot of learning to do on this myself.
I used this as a jumping off place
http://www.reef-aquarium.net/resources/chemicals/kalkwasser.html
http://www.aquarticles.com/articles/sal****er/metelsky_kalkwasser.html


--
Toni
http://www.cearbhaill.com/reef.htm

[Wayne Sallee]

Just drip enouph lime water to keep up with evaporation.

When mixing lime water, use more lime than will disove, so that you have a good
strong soution. exece will settle out after mixing.

When dripping, you want to take it slow at first since you are new at it, but
slowly as you get the hang of it, and get more familiar of how many drips per
second you need for your system, you increase the rate, untill you are
comfortable with it. For my 120 gallon I drip all day (it's simpler). I drip
about 1.5 drips per second.

Wayne Sallee