Need GFO Help

[Sig32]

Not sure if I’m posting in the correct forum, if not, my apologies and can a mod please direct me. Now on to my issue. I recently used Chemipure Elite (11.74oz) to treat my 65 gallon reef tank for phosphates, a chronic condition (0.21 ppm via Hanna Checker). Within a few days, phosphates began to drop. After 4 weeks, phosphates were at 0.04 ppm and the tank was looking great. Phosphates remained at this level for approximately three weeks before it began to rise again.

I decided that since I had such good results that i would try GFO alone, since it is more cost effective. I started with 10 tablespoons based on the directions of one 2-3 tbs/10 gallons. After four weeks my phosphates are still 0.19 ppm (no change). I assume that I need more GFO, but I am afraid to over treat and kill everything. I have searched endlessly to find the actual amount of GFO in Chemipure Elite, since I know that amount worked great, but I can’t find anything.

Does anyone know this amount or can you advise on how I should proceed, or should I just stick to using Chemipure Elite? Thanks in advance for your help.

 

[SPR1968]

With any GFO you need to change it when it’s spent or it won’t work. The only way to know is to test.

In my systems I change rowaphos every 2 weeks on 1 system, and every 5 weeks in the other (due to different amounts being used) and it keeps phosphate locked down at less than 0.03

 

[Sig32]

Thanks for the reply. Considering the phosphate level never dropped, is it possible that it was “spent” within a day of adding it? If so, how do I best find the amount needed. GFO is new to me as I’ve only used CP Elite in the past. It was simpler since I just drop a bag in a chamber and it does its thing until depleted.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for the reply. Considering the phosphate level never dropped, is it possible that it was “spent” within a day of adding it? If so, how do I best find the amount needed. GFO is new to me as I’ve only used CP Elite in the past. It was simpler since I just drop a bag in a chamber and it does its thing until depleted.

Yes, GFO can easily be spent in a day if phosphate is high enough and flow through it is adequate.

OTOH, you may be exporting phosphate, but are just not exporting enough to match the additions from foods and release from rocks and sand as you try to drop the level.

Going slow is best though.

 

[Sig32]

Thanks for the reply. Would you happen to know the amount of GFO in CP Elite (to dose that amount since it worked without issues)? Would you suggest I increase my treatment to 3 tbs/10 gallons or would that be too much? Any guidance on how to best proceed would be appreciated.