I'm having issue keeping my phosphates down in my 80 gallon tank, tank turned a year old last month. My phosphate levels currently sit between 0.30 to 0.60 ppm. Which wouldn't be a problem, if I didn't have green hair algae growing on the rocks. For now I've been manually removing the GHA and scrubbing the rocks I can with diluted hydrogen peroxide.
I do fairly regular water changes, about 15 gallons weekly. More recently I've tried using ROWAphos (in reactor) and Phoshpat-E to slowly bring down my phosphates. I've been doing the ROWAphos for about ~3/4 weeks. Phoshat-E was done for a 1/2-week dose about 3 weeks ago. Even with these measures, I can't seem to get my phosphate under 0.3 ppm.
I feed 1-cube of frozen about 3 times a week (rinsed). And also have auto feeders that feed a small amount of Seaweed Extreme + TDO pellets (once a day), and another with spirulina flakes (3x daily). I used to dose phyto until I noticed my phosphates climb up.
Looking at my testing history my phosphate levels have slowly been increasing over the past year. I usually test weekly, and would test more often once I started the reactor and phosphat-e to prevent bottoming out.
When I look at the statistics the testing numbers from 2024 contrast significantly when compared to 2025. Averaging 0.11( where I'd like to be) to 0.32 ppm this year.
I'm a bit conflicted on whether or not I should continue with GFO and/or chemical approach to lower my phosphates. I don't think I'm overfeeding my tank in a way that would warrant these high phosphate numbers. I have a nano 16G that sits at about 0.06 ppm, which has a similar feeding regime, but has been running for less than a year.
The only thing I could think of that might be causing my high phosphates is the caribsea arches I have in the tank. It would be easy to point at those rocks and say that they are "leaching" phosphates. Or maybe my filtration is just lacking? My nitrates averaged 22 ppm last year, and are up to 27 ppm this year.
Should I keep using reactor/chemicals to bring down the nutrients? Do larger water changes going forward? Replace the Caribsea arches?
I do fairly regular water changes, about 15 gallons weekly. More recently I've tried using ROWAphos (in reactor) and Phoshpat-E to slowly bring down my phosphates. I've been doing the ROWAphos for about ~3/4 weeks. Phoshat-E was done for a 1/2-week dose about 3 weeks ago. Even with these measures, I can't seem to get my phosphate under 0.3 ppm.
I feed 1-cube of frozen about 3 times a week (rinsed). And also have auto feeders that feed a small amount of Seaweed Extreme + TDO pellets (once a day), and another with spirulina flakes (3x daily). I used to dose phyto until I noticed my phosphates climb up.
Looking at my testing history my phosphate levels have slowly been increasing over the past year. I usually test weekly, and would test more often once I started the reactor and phosphat-e to prevent bottoming out.
When I look at the statistics the testing numbers from 2024 contrast significantly when compared to 2025. Averaging 0.11( where I'd like to be) to 0.32 ppm this year.
I'm a bit conflicted on whether or not I should continue with GFO and/or chemical approach to lower my phosphates. I don't think I'm overfeeding my tank in a way that would warrant these high phosphate numbers. I have a nano 16G that sits at about 0.06 ppm, which has a similar feeding regime, but has been running for less than a year.
The only thing I could think of that might be causing my high phosphates is the caribsea arches I have in the tank. It would be easy to point at those rocks and say that they are "leaching" phosphates. Or maybe my filtration is just lacking? My nitrates averaged 22 ppm last year, and are up to 27 ppm this year.
Should I keep using reactor/chemicals to bring down the nutrients? Do larger water changes going forward? Replace the Caribsea arches?
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