Constantly changing Rowaphos

taki123 · Dec 24, 2022

Hi guys,

I have a Redsea 425XL mixed reef and I seem to be struggling with phosphates. With Rock taking up some volume I have around 350L of water in the tank.

Here are my current readings:
Nitrate = 2.6ppm
Phosphate = 0.12ppm
Alk = 8.4dKh
Cal = 430ppm
Magnesium = 1370ppm
Salinity = 35ppt

In my fluidised reactor I add around 75-100g of Rowaphos at a time. The next day my reading drops to around 0.01/0.02ppm.
However 3 days later I am back to 0.12ppm and this has happened for the last 3 times I changed the Rowaphos.

I heard it only needs changing every month usually so why is mine acting so strange?

Reef Psychology · Dec 24, 2022

Your numbers aren’t that bad imo if you’re not all about SPS, even then…. What are you feeding? Some foods are known for phosphates. I don’t have a lot of experience with fighting phosphate, but I do use rowaphos and see the same thing. Large dip at first then it trails off. That’s why people say go slower so you don’t shock the system with a large down turn. Add it over time to gradually decrease levels. You probably have a large influx somewhere.

taki123 · Dec 24, 2022

Reef Psychology said:
Your numbers aren’t that bad imo if you’re not all about SPS, even then…. What are you feeding? Some foods are known for phosphates. I don’t have a lot of experience with fighting phosphate, but I do use rowaphos and see the same thing. Large dip at first then it trails off. That’s why people say go slower so you don’t shock the system with a large down turn. Add it over time to gradually decrease levels. You probably have a large influx somewhere.

So I the afternoon I feed pellets or algae flakes then in evening I feed one cube of frozen food. I don’t rinse the frozen food however just put it into a feeding basket frozen

Spare time · Dec 24, 2022

Was the rock or sand previously dried out?

taki123 · Dec 24, 2022

Spare time said:
Was the rock or sand previously dried out?

No it wasn’t

Reef Psychology · Dec 24, 2022

taki123 said:
So I the afternoon I feed pellets or algae flakes then in evening I feed one cube of frozen food. I don’t rinse the frozen food however just put it into a feeding basket frozen

I have a somewhat related issue. Maybe this will give you some ideas until someone with more experience chimes in. I have 0 nitrates and 0.03 phos and I want to raise nitrates while keeping phosphate ~0.01-~0.03. This is an SPS tank. I feed 3-4 a day mostly frozen, pellets and Reef-Roids (known phosphate source). And I actually dose nitrates once a week. The tank is only 45 days old and I haven’t had an ugly stage. I use Aquaforests’ probiotics, AF Bio Fil, ZeoMix, carbon, Rowaphos (only a teaspoon), and Seachem Matrix seeded from another tank.

Long story short, I’m trying to keep phosphate stable while trying to raise nitrates. This is an experiment in aggressive ‘aging’. So I’m not sure if rinsing your frozen foods, blowing off rocks before siphoning the sand bed, wet skimming and cleaning mechanical filtration will solve your issues.