Ongoing Algae with low nutrients. An experienced reefer needs help!

glb · Jul 26, 2023

I’ve been battling what looks like gha and turf algae for several months in my tank. I know the usual causes because I’ve been doing this for years, but my nutrients have not been elevated before or during the outbreak. My nitrates sit at 0-1ppm and the phosphate is never higher than .3ppb. I thought it might be silicates so I changed out the old rodi filters. I also tested the tank water with a Hanna Checker and the silicates were zero. I know algae can eat up nutrients in a tank but I never had the high nutrients that usually starts the problem. I’ve been manually removing the gha but the turf algae doesn’t come off the rock easily. My corals have not been negatively affected. All the livestock is fine. I bought emerald crabs and a foxface to help with the algae but they don’t seem to be making a dent. I don’t overfeed, and only have 6 fish in the 40g tank. There have been no deaths of fish or invertebrates that I know of.

My next step is to keep the lights off for 3 days to see if that does the trick.

For the life of me, I can’t figure out why I got the algae and why it won’t go away. Is there any other reason I haven’t considered? I know turning off the lights is a temporary fix if the underlying problem isn’t addressed. Maybe once it’s gone it will stay away since my nutrients are low. Below are some picks after I pulled off a bunch of it.

Any help is appreciated!!!

CoralB · Jul 26, 2023

Is there stringy hairs with bubbles ? Any way you can get a pic with whites on . If I had to guess from these pics I would guess Dino’s which usually come from zeroing out phosphates and or nitrates . Stating which test kits used to test phosphates and nitrates and a pic with white lights to better identify would be of great help. Also Mexican turbo snails and tuxedo urchins work best imo on gha

glb · Jul 26, 2023

CoralB said:
Is there stringy hairs with bubbles ? Any way you can get a pic with whites on . If I had to guess from these pics I would guess Dino’s which usually come from zeroing out phosphates and or nitrates . Stating which test kits used to test phosphates and nitrates and a pic with white lights to better identify would be of great help. Also Mexican turbo snails and tuxedo urchins work best imo on gha

Thanks! They’re not dinos, I’ve had those before. They are a combo of dark green hairy algae attached to the rocks and a small tufted algae that’s really hard to remove. I have the lights off now but will take a pic tomorrow.

The_Paradox · Jul 26, 2023

From the limited photos that looks significant enough I doubt your clean up crew is gonna catch up. If it were me I would hit it with fourteen day fluconazole treatment. Once you get it in check clean up crew should be able to take over and handle new growth.

glb · Jul 27, 2023

The_Paradox said:
From the limited photos that looks significant enough I doubt your clean up crew is gonna catch up. If it were me I would hit it with fourteen day fluconazole treatment. Once you get it in check clean up crew should be able to take over and handle new growth.

Thank you!

glb · Jul 27, 2023

The_Paradox said:
From the limited photos that looks significant enough I doubt your clean up crew is gonna catch up. If it were me I would hit it with fourteen day fluconazole treatment. Once you get it in check clean up crew should be able to take over and handle new growth.

Do you recommend reefflux? Also, can you buy non-reef fluconazole capsules (for people)? The Reef fix is pricey for how much you need. Thanks!!!

The_Paradox · Jul 27, 2023

glb said:
Do you recommend reefflux?

Wherever you can get it the easiest/cheapest. I’ve always dosed ~ 15% under recommended amount and had nothing but good luck. Last year had to dose a tank for the same issue you are having. Low nutrient but GHA got into zoas and acans. First 7 days there was little change. Days 7-14 algae just melted away. Used it two other occasions but that was 6+ years ago. Results were the same but I do not remember the time line.

Before you dose you may need to get supplemental food for any algae exclusive animals. I guess the better advice is make sure any algae exclusive animals you have will take prepared food.