Does GHA work like other algae in removing phosphate, nitrate and other bad stuff? If so, by continuing to harvest the GHA as it grows, am I not removing it's food supply, and eventually starving it out?

I'm nine months into my first nano, and have had GHA for about 3 months. Ten years ago, I had a 55g tank that had similar GHA in the first year, but later it worked itself out.

It is consuming those nutrients; however, they were allowed to build up to the point where you had a problem. Your assumption will hold true if you reduce your bio-load and/or feeding.

What seabass said...



If you have a recurring excess nutrient problem, then no, it will not help. If you have a one time excess nutrient problem, then sure, it'll die back off.

I'm still not sure where the root of the problem resides. There are three small fish in my NC24: orange spot goby, tail spot blenny, and a fathead anthias. Nitrate and phosphate are undetectable with API testing. 10% weekly water changes, and every other day feeding.

RO water comes from LFS, and could have some contaminant. Can long term curing of rock and sand be a factor? Does this process release nitrate/phosphate?

I'm using a pretty common filtration setup including floss + chemipure in chamber 1, chaeto refuge in chamber 2. I have avoided skimming up to now, but am considering adding one.

Food is probably the biggest source of phosphate. Plus, any bio-load produces ammonia, which is quickly converted to nitrite and then to nitrate. The algae is utilizing these nutrients; and any denitrifying bacteria that is supported by your live rock will also utilize available nitrate.

Other bio-filters cannot process nitrate (like bio-balls or any mechanical filter that's left in for too long, including floss and Chemi-Pure). Improper sand beds can also cause problems by trapping detritus or developing oxygen deprived zones which don't properly support denitrifying bacteria.

A skimmer can help by reducing organics before they are broken down into nitrate. However, I would probably start by increasing my water change volume/frequency. Then be patient.

Note: An Anthias is not a good choice for the size of tank a feeding schedule that you have.

Thanks Seabass.

I'm no biologist, but have a fair handle on the denitrification process. I'll take the advise and try to increase the water change schedule, plus start changing floss out twice weekly.

On the anthias note, this is a sunburst anthias. I have a nice cave that it enjoys.
I've been curious to the feeding needs. Rod's food has been successful, but I'm thinking this specimen may need feeding more often. Any suggestions on supplementing the diet for this guy?

Rods food has been associated with high phosphate levels, as well gha's main nutrient seems to be phosphate

Usually food and your wc water are the main culprits for the cause of gha, make sure your using tds tested ro/di

a reason you're not detecting PO4 and nitrate could be if you're algae problem is bad enough (i'm assuming it is since you're posting here ) it is consuming those nutrients at a rate fast enough to make them undetectable... when i did planted tanks for instance i dosed to .8 PPm PO4 daily and 2 hours after the lights came on it tested 0. add food wait 15 mins then test for things