Doc’s oops I did it again 200 gallon

Dr.DiSilicate

Great White Shark
M.A.S.C Club Member
ex-officio
Ok Dave I checked my phosphate... I guess I should do this more than every 9 months. I do have algae in the glass pretty quickly so as predicted my levels are a bit high. .16ppm according to the average of two Hanna checker. I’d like to keep it about half that I think. I’ll do a bit more water changes and I ordered some GFO. Haven’t run any of that for a few years but this tank is still less than a year old so... a little extra work is needed.


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Djmm1177

Butterfly Fish
M.A.S.C Club Member
Ok Dave I checked my phosphate... I guess I should do this more than every 9 months. I do have algae in the glass pretty quickly so as predicted my levels are a bit high. .16ppm according to the average of two Hanna checker. I’d like to keep it about half that I think. I’ll do a bit more water changes and I ordered some GFO. Haven’t run any of that for a few years but this tank is still less than a year old so... a little extra work is needed.


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Looks like your tank likes the high phosphate ! Mine are at .60 but my alk is at 10.5 but it’s happy! I run phosgard and change it every four days.


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Dr.DiSilicate

Great White Shark
M.A.S.C Club Member
ex-officio
Looks like your tank likes the high phosphate ! Mine are at .60 but my alk is at 10.5 but it’s happy! I run phosgard and change it every four days.


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My alk is closer to 7.5 and the coral is happy. I think I’d like to get mine to about .1 so around 3/4 what they are now. I started to run a little gfo to get them down slowly mostly to keep the algae off the glass. No perfect answer here but I know phosphate (too high or too low) can be a limiting factor for coral growth and color as well.

My DI resin was pretty old too so I changed that out today as well.


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jda123

Dolphin
M.A.S.C Club Member
Use just a few tablespoons and change it ever day or two. This slow removal, although a pain, is better than using more and having a P spike downward when the GFO soaks up a bunch and then a spike back upward when the aragonite releases a bunch. A spike might be OK... or two, but I would not do many more than this.

.005 is the typical NSW level (2 ppb) and that is not growth limiting. I like to stay between 2 and 5 ppb on a Hannah Ultra Low. The only downside to this is that coral growth explodes and also the coralline has to be scraped more. I would keep your alk more around 6.0 if you want to go below 2 ppb... like the Zeovit people do. :(

.16 is no huge issue, so you don't have time to be in a hurry here... steady as she goes.

Also, for the masses, don't forget that GFO bind is reversible. If you put GFO that has bound some phosphate into water that had less than the original source, the GFO will unbind some. This is particularly important in a tank where you put some GFO on and then changed some water... the GFO will release P back into the freshly changed water and you will be right where you were before. ALWAYS change your GFO when you change some water. Al Oxide has this same relationship.
 

Dr.DiSilicate

Great White Shark
M.A.S.C Club Member
ex-officio
Doug, yea I just used a little bit. I never use the suggested amount and have no desire to go really low nutrient. I’ll change it out this weekend when I do a water change. Thanks for the additional information!


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TheRealChrisBrown

Reef Shark
M.A.S.C Club Member
ex-officio
that GFO bind is reversible. If you put GFO that has bound some phosphate into water that had less than the original source, the GFO will unbind some.
Do you know if this is also true for RowaPhos? I thought one of it's claims to fames was that it doesn't unbind phosphate at all? Even when it is fully saturated and can't take up any more... Just curious
 

jda123

Dolphin
M.A.S.C Club Member
Rowa is just another kind of GFO, made in the same factory as all of the others. All GFO will unbind and bind to "equilibrium" with the outside water, so if you lower the water level it will unbind... if you raise the water level, it will bind more. I did not know that they claimed this, but it is untrue if they did.

There are only two places on earth that make GFO... both make the higher binding stuff and the lower. ROWA is the same as ANY other high capacity GFO, so don't pay more for it. The regular stuff is all the same too.

Nobody will ever fully saturate GFO. It will only bind to "equilibrium" and then bind no more. If you have 10.0 ppm P, then it will bind a lot more than if you have .1, but in either case, once it is bound to equilibrium, it will bind no more. I think that you need something like 1000 ppm of P in a solution for GFO to bind completely - this level would be death for most living things.

Aragonite has the same relationship. Everybody with aragonite in their tanks has a bunch bound in the rock and sand. Dry rock usually comes packed with the stuff. As you lower the water level with GFO or water changes, the aragonite will release some back to nearly where you were before. It can take much GFO and many changes to actually lower the amount in the tank. This is why I am worried for every person that has stoped skimming, running a fuge or changing water with this new paradigm thinking that P is a coral "food" and that more is better (it is not... neither food nor better to have more)... they will be fighting to remove it one day and probably need several 5 gallon buckets of GFO to catch back up over many months.

Dr. Holmes-Farley had a nice long post on this once. Part is his day job is understanding phoshate metabolism for some drug, so he is very helpful. He is kinda on sabbatical, but all of stuff is still out there.

/hijack
 

Dr.DiSilicate

Great White Shark
M.A.S.C Club Member
ex-officio
Well after 5 days or so with around 1/3 cup of the gfo I did a water change of about 10 gallons and changed out the gfo last night. Upon measurement this am my phosphate is down by 2/3! It’s just about where I want it. I’ll continue to track it for the next few weeks. The algae on the glass is growing much more slowly... just trying to maintain now rather than lower.


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