Science/Chemistry question:

Let's assume we have relativelly high level of phosphates in
the 58 gallon tank. There are three ways to deal with the problem:
- partial water exchange with let's say 12 gallons water with no phosphates
- usage of phosphate removal media like PhosBan, Phosar etc...
- partial water change AND phosphate removal filters.

Intuition would tell me that the third option will be most effective.
But what to do first? Should I put phosphate removal medium and
extract as much phosphate as phosban is able to and then change water?
Or maybe do water change first, and then lowered phosphate levels
treat with the phosban? Or maybe it does not really matter?

Pszemol wrote:
Let's assume we have relativelly high level of phosphates in
the 58 gallon tank. There are three ways to deal with the problem:
- partial water exchange with let's say 12 gallons water with no phosphates
- usage of phosphate removal media like PhosBan, Phosar etc...
- partial water change AND phosphate removal filters.

Intuition would tell me that the third option will be most effective.
But what to do first? Should I put phosphate removal medium and
extract as much phosphate as phosban is able to and then change water?
Or maybe do water change first, and then lowered phosphate levels
treat with the phosban? Or maybe it does not really matter?

btw, it also drive me nuts when the recommendation is to "replace your
evaporated water first" then do a water change. You want to suck out
waste water at it's highest concentrations and then refill will both
salt and fresh water to get you back to your SG. Of course, that's why
I use two trash cans rather then one.

But, to each their own... You can always use larger or more frequent
water changes to accomplish the same level of exchange, but it seems
like a waste of salt and effort to me.

--Kurt

KurtG wrote:

btw, it also drive me nuts when the recommendation is to "replace your
evaporated water first" then do a water change. You want to suck out
waste water at it's highest concentrations and then refill will both
salt and fresh water to get you back to your SG.

And I'm the opposite. I mix up my salt water to the correct SG, drain my tank
down to a specific point on the glass (ie. 25 gallons low), and add the new
water to top it back off. If the water level in the tank is low before the
change, I won't actually be draining off 25 gallons, and the SG will be a bit
high after the water change. It could get quite high after several water changes.

George Patterson
If you torture the data long enough, eventually it will confess
to anything.

George Patterson wrote:
drain my
tank down to a specific point on the glass (ie. 25 gallons low),

Yep, it's less efficient, but it does enable the mark on the tank
technique which seems to be more or less standard based on every book
I've read.

I opted against this for two reasons:

1- less efficient at removing waste as you're diluting your tank before
draining a percentage.

2- what if you over drain by accident? If you have enough extra salt
water, you're in luck; otherwise, you're mixing up more salt water.

3- you're limited to draining only xx%. What if you want to do lower
cleaning and/or more siphon cleaning?

I'd rather keep it a bucket and use it for make up (if needed) after the
silt settles a bit. If you do that, there's no advantage to the mark on
the tank technique and a few disadvantages.

I guess it's less of a big deal now as I keep my evaporative makeup at
less then a gallon.

--Kurt

Actually the only thing that you are accomplishing,
is that you are waisting less RO water. That's the
only thing that you are accomplishing.

If you do a 15% water change, then you are still
doing a 15% water change even if the water is more
concentrated.

If you add 30 gallons worth of sea water strength
water, or it's equivalent value of diluted strength,
you are still only removing from your tank a 30
gallon equivalent of phosphate.

Wayne Sallee
Wayne's Pets


KurtG wrote on 3/13/2007 11:51 AM:
George Patterson wrote:
drain my
tank down to a specific point on the glass (ie. 25 gallons low),

Yep, it's less efficient, but it does enable the mark on the tank
technique which seems to be more or less standard based on every book
I've read.

I opted against this for two reasons:

1- less efficient at removing waste as you're diluting your tank before
draining a percentage.

2- what if you over drain by accident? If you have enough extra salt
water, you're in luck; otherwise, you're mixing up more salt water.

3- you're limited to draining only xx%. What if you want to do lower
cleaning and/or more siphon cleaning?

I'd rather keep it a bucket and use it for make up (if needed) after the
silt settles a bit. If you do that, there's no advantage to the mark on
the tank technique and a few disadvantages.

I guess it's less of a big deal now as I keep my evaporative makeup at
less then a gallon.

--Kurt

I don't think I follow your point.
The guy wants to know if he should use a phosphate remover before or after
the water change. Then the topic changed to volumes and everyone was on
topic.
I am sure that performing a water change before adding any remover is the
only way to go.
I understood every reply posted, then you came along!
Either you didn't write what you were thinking or you were drinking before
posting.
It just doesn't make sense.
A 15% water change of "concentrated" water (I will assume you meant with a
high reading of PO4) you claim that is the same 30 gallons of diluted water?
You must be on drugs!
If this isn't what you meant I am sorry but you have us used to the most
ridiculous comments.
Now, read this again and tell us what it means...

"If you add 30 gallons worth of sea water strength water, or it's equivalent
value of diluted strength, you are still only removing from your tank a 30
gallon equivalent of phosphate."

In Mexico that is called a CANTINFLADA. Any Mexican here will know what I
am talking about. (BTW, I am not Mexican but like Cantinflas the comedian)

iy

"Wayne Sallee" wrote in message
ink.net...
Actually the only thing that you are accomplishing, is that you are
waisting less RO water. That's the only thing that you are accomplishing.

If you do a 15% water change, then you are still doing a 15% water change
even if the water is more concentrated.

If you add 30 gallons worth of sea water strength water, or it's
equivalent value of diluted strength, you are still only removing from
your tank a 30 gallon equivalent of phosphate.

Wayne Sallee
Wayne's Pets


KurtG wrote on 3/13/2007 11:51 AM:
George Patterson wrote:
drain my
tank down to a specific point on the glass (ie. 25 gallons low),

Yep, it's less efficient, but it does enable the mark on the tank
technique which seems to be more or less standard based on every book
I've read.

I opted against this for two reasons:

1- less efficient at removing waste as you're diluting your tank before
draining a percentage.

2- what if you over drain by accident? If you have enough extra salt
water, you're in luck; otherwise, you're mixing up more salt water.

3- you're limited to draining only xx%. What if you want to do lower
cleaning and/or more siphon cleaning?

I'd rather keep it a bucket and use it for make up (if needed) after the
silt settles a bit. If you do that, there's no advantage to the mark on
the tank technique and a few disadvantages.

I guess it's less of a big deal now as I keep my evaporative makeup at
less then a gallon.

--Kurt

KurtG wrote:

2- what if you over drain by accident? If you have enough extra salt
water, you're in luck; otherwise, you're mixing up more salt water.

I wouldn't worry about this one; I've used my technique for about 30 years and
never had this happen.

George Patterson
If you torture the data long enough, eventually it will confess
to anything.

George Patterson wrote:
KurtG wrote:

btw, it also drive me nuts when the recommendation is to "replace your
evaporated water first" then do a water change. You want to suck out
waste water at it's highest concentrations and then refill will both
salt and fresh water to get you back to your SG.


And I'm the opposite. I mix up my salt water to the correct SG, drain my
tank down to a specific point on the glass (ie. 25 gallons low), and add
the new water to top it back off. If the water level in the tank is low
before the change, I won't actually be draining off 25 gallons, and the
SG will be a bit high after the water change. It could get quite high
after several water changes.

George Patterson
If you torture the data long enough, eventually it will confess
to anything.


Huh?

Don't see what advantage there is to that - what advantage does having a
25G low mark give you?

Do you generally only have 25 Gal available to replace with?

I do it this way-

take water out, THEN adjust SG to norm, THEN refill with new sal****er.

I do many many micro changes (plus I only have a 20 gal nano anyway...)
so I never thought about putting a mark for a specific amount to drain.

I recently started doing 1/4 gallon (ie: 1 qt) change per day, every
day, on schedule at 11:00 pm before I go to bed -- part of my nightime
routine -- comes right after "brush teeth" on the checklist. seems to
work quite well for a small tank - I can do the wtare change in under 30
seconds using a plastic 1 qt measuri8ng cup.

Add Homonym wrote:

Do you generally only have 25 Gal available to replace with?

Yes. I make up 25 gallons at a time.

George Patterson
If you torture the data long enough, eventually it will confess
to anything.

"KurtG" wrote in message ...
btw, it also drive me nuts when the recommendation is to "replace your
evaporated water first" then do a water change. You want to suck out
waste water at it's highest concentrations and then refill will both
salt and fresh water to get you back to your SG. Of course, that's why
I use two trash cans rather then one.

Recomendations are just that: recomendations... :-)
You do not have to follow recomendations if you KNOW WHAT YOU ARE DOING :-)
And in this case you are of course right. I do a water change first,
I use empty Instant Ocean salt buckets. I prepare two full of sal****er
and use third for drain. If you replace same amount of concentrated
water with diluted one your salinity will drop, so you need to drain
little less old water to replace it with the new...

It takes some practice, so for beginners recomendation is good: after
replacing evaporated water and bringing salinity to normal you simply
replace same amounts of old water with new water and salinity stays unchanged.

But, to each their own... You can always use larger or more frequent
water changes to accomplish the same level of exchange, but it seems
like a waste of salt and effort to me.

Exactly - larger water changes are simply much more effective.
And this is not linear equation: replacing twice 10% of water
does not equal one 20% water change. 20% is much more effective.