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

[LeanneP]

I have a 90 gallon mixed reef tank and I have had phosphates as high as .22. The main reason was my R/O water, but I have solved that issue. I now have them at .12 and I have been using a phosban reactor. I used a cup of Rowaphos and in 2 days I have used it up which seems pretty crazy to me. I have 9 fish and about 6 RBTA which I am sure are contributing to the phosphates. I can't reach the anenomes as they are all at the back of my tank. I have been running the reactor for a month but just solved my water problem last week. Should I just be filling up my reactor so that the rowaphos lasts longer? Any suggestions on cheaper GFO to use?

[intarsiabox]

Are you having algae issues? If not, have you tried a different test kit?

[LeanneP]

Yes, I have cyano right now and I use a hanna checker so it is pretty consistent when I am testing.

[warriorcookie]

Sounds similar to what i just went through.

What are your nitrates at? Undetectable?

[LeanneP]

Originally Posted by warriorcookie

Sounds similar to what i just went through.

What are your nitrates at? Undetectable?

My nitrates are .25 so not much. Did you get your phosphates down and if so how? I am thinking it might take some time since they have bee high for a bit but just hoping they do come down since I have such a high bio load with so many nems.

[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

[warriorcookie]

Originally Posted by LeanneP

My nitrates are .25 so not much. Did you get your phosphates down and if so how? I am thinking it might take some time since they have bee high for a bit but just hoping they do come down since I have such a high bio load with so many nems.

Well, it was a bit of an experiment for my tank and I'm only a few weeks in but the results came quick. My issue was my NO3 was undetectable, and my PO4 was too as long as I used GFO. As soon as I ran out of GFO my PO4 would skyrocket fast but NO3 would stay at 0.

Wish I had more time to go further in depth, but start with the basics: weekly/bi-weekly water changes including vacuuming the sand and blowing off the rocks, good skimmer, don't let uneaten food sit, rinse food before feeding, good cleanup crew, etc.

It appears that an imbalance between nitrates, phosphates, and carbon will cause cyano as it was a constant fight in my tank.

First I started feeding the fish and corals a lot more than ever. PO4 raised quickly (over .2ppm) and eventually finally NO3 slowly started coming up. Then I resumed dosing carbon and bacteria. I use prodibio. I'm sure MB7 or the like with vodka or sugar would work too. Make sure you read on the proper way to dose carbon before you start.
Then I started to dose NaNO3 to bring up my NO3 to around 2ppm. As soon as it got high enough I had a bacterial bloom and the next day my PO4 was .02ppm without GFO! All I've had to do is keep my NO3 between 1-2ppm and it keeps the PO4 down.

I'm hoping I can keep this balance moving forward without having to dose NaNO3 on a regular basis, but we'll see. It is extremely cheap if I do end up having to dose.

The idea is bacteria need to consume nitrate, phosphate and carbon. I was putting plenty of bacteria in the tank, giving them lots of carbon and phosphates, but they were starved for nitrates. As soon as I gave them more nitrates they gobbled up the phosphates. Then my skimmer started pulling out some pretty thick and stinky skimate!