High phosphates-using reactor and can't get them down

[LeanneP]

Originally Posted by gregzz4

When you say you've used up a cup of ROWA in a couple days, what exactly do you mean? How did you come to this conclusion?

My experience with GFO has been to use smaller amounts and change it more frequently. IE: instead of BRS's suggestion of using 0.86 cups/225mls or so per 100g, I started running 100mls (thanks Mindy). I found this helped and feel it's due to not adding so much iron to the tank from the GFO.


I change my GFO every 4 weeks, and stir it every week or two to make sure it's still getting full contact.

Doing this, I can drop my PO4 from 0.09 to zero in no time.
I've dropped it from 0.19 to 0.05 in just over a week.
And if I run any more than the 100mls it will actually strip the tank clean.
Then I get other issues, so sometimes less is more

I read a thread on Rowaphos that 120 mls which is just under half a cup would reduce phosphates by .05 in a 75 gallon tank. Mine is 90 with a 10 gallon sump so I originally used 125 mls. I was getting. 04 coming out of the reactor so I thought I needed to use more. I put in a cup 2 days àgo and had a 0 reading . Today I checked and it was .09 so I stirred the GFO to make sure the reactor was working right but I still got the same reading. I am assuming that it is used up? I am new to using the reactor so if I am .doing something wrong it would be good to know. Should I only be using 100 mls at a time?