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

Pszemol wrote:

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?

Do the water change first. According to the info that comes with RowaPhos, the
contents of the package will remove a certain amount of phosphates. When used in
a phosphate reactor or filter, you just leave it there until phosphate levels
start to rise again. If the phosphate level in the tank is lower due to a recent
water change, the RowaPhos will last longer. I assume that this would also be
true of other phosphate removers, such as Phosban.

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

"George Patterson" wrote in message news:0IzJh.2285$8u4.690@trnddc08...
Do the water change first. According to the info that comes with RowaPhos, the
contents of the package will remove a certain amount of phosphates. When used in
a phosphate reactor or filter, you just leave it there until phosphate levels
start to rise again. If the phosphate level in the tank is lower due to a recent
water change, the RowaPhos will last longer. I assume that this would also be
true of other phosphate removers, such as Phosban.

The problem is that I noticed phosphates do not go below 0.05 in my tank.
I do not know if this is the lowest level PhosAr can pull them down or
it is simply not efficient enough... Maybe I need to replace it with a larger
amount of media in the reactor. Right now I use about 50 grams of PhosAR
in my 58 gallons reef placed in a Phosban Reactor powered with MaxiJet900.

If the 0.05 was the lowest level achievable with the phosphate removal
than it would be sensible to use new remover first, bring phosphates
down to 0.05 and then do a water change to bring them even lower :-)

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.

"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.

Pszemol wrote:

The problem is that I noticed phosphates do not go below 0.05 in my tank.
I do not know if this is the lowest level PhosAr can pull them down or
it is simply not efficient enough... Maybe I need to replace it with a
larger
amount of media in the reactor.

Perhaps there would always be a trace due to dead spots in the tank (water that
never gets pulled through the reactor).

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

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.

George Patterson wrote:
Do the water change first.

I wonder what happened to my other post, but I agree with George. You
want to export as much Phosphate as possible with the water change, so
you do that before starting the phosphate reactor. The reactor is a
much slower process.

--Kurt