I've had a pretty regular problem with apparently-not-tasty GHA in my display tank pretty much ever since I set it up. It's definitely GHA, not bryopsis, but I haven't found anything that will eat it consistently (red/blue-legged hermits, trochus, astraea, turbo, margarita, even a lawnmower blenny).

i have zero detectable nitrates and phosphates. i use 0 TDS RO/DI. I also run Rowaphos under my drain line in a filter sock, and I skim fairly wet these days. also just started running some carbon yesterday, just to see what would happen.

I have a giant pile of chaeto in my fuge over a DSB. the chaeto, however, has been cohabiting the fuge with a fair amount of GHA living under and among the chaeto.

i never really felt like this was a huge problem, but i recently was doing some reading, and i read that if the nuisance algae is inhabiting your macroalgae, then you may need to toss the macro and clean out the fuge along with the display in order to get rid of it.

Does anyone have any thoughts on this?

I pull my macro and clean out the micro as I separate out the overgrowth.

Have you tried chemi-pure? I remember reading somewhere that using chemi-pure brought algae growth to a stop...even chaeto. The remaining gha you'll need to manually scrub off if your cleaners are not doing it. GL

Nitrates and phosphates...

Lots of water changes to remove nitrates and chemi-pure elite and or GFO for phosphates. Phosphates can be in your salt mix and food, weekly water changes (in my experience) wont be enough to remove them (and not quick enough after they get in).

i'm using rowaphos, which is GFO like that found in chemi-pure elite.




i'm measuring 0 on both nitrates and phosphates. i realize the algae can mask those, but i measure 0 even after i scrub out a bunch of the algae.

and, like i said, i'm running rowaphos as GFO.



what about the micro in the macro that you can't see?

Test a fresh batch of saltwater for nitrate phosphate. How long has it been since you changed your rowaphos, how much are you using and how are you using it (reactor, bag, etc)?

What type of lighting and how old are the bulbs?

i just added the rowaphos, starting maybe 4 weeks ago, and gradually working up to the current amount (i am not sure exactly how much i'm using). it's in a mesh bag in the bottom of my filter sock under my drain line.

lighting is 150w HQI + 2x24w T-5 actinics. i'm running the halide 7 hours a day, actinics about 10. bulbs are all original stock and are all 6 months old.

i haven't tested the salt water for nitrate/phosphate. i'd be surprised about that, though - my LFS uses D-D salt with kidney dialysis machine-grade RODI.