Cyano and GHA won't dissapear

isufishtank · May 8, 2019

Hello! I've had my tank for about 5 months and have had constant struggles with Cyano and GHA despite having 0 Ammonia, 0 Nitrite, 0 Phostphates, and near zero nitrate. I am using an API test kit which I hear are inaccurate; Is the test kit just off? From what I understand, GHA and Cyano rely on nutrients in the water to grow. If I have little to no nutrients, how are they growing? I can say that the Cyano seems to come in "cycles", ie it will almost completely disappear before returning in full force a week later. I am planning on getting my water tested at a LFS in the next week, as well as doing a large water change (>50%). As a perhaps related note, my coral have been suffering recently with the return of the Cyano. Portions of my birdsnest have bleached and are now growing algae. There is an odd mix of coral that seem to be doing well (my acan, duncan, mushroom, and some green SPS) and some that are doing poorly (Acro died, bubblegum digi, palys, setosa). What would cause some of these coral to bleach/die and others to be fine? Really hoping a big water change will help, but any other advice is appreciated! thanks.

dansreef · May 8, 2019

A couple of things to think about, an existing outbreak of GHA and Cyano will artificially lower the tests you do for Nitrate and Phosphates potentially....and then the fact that API is not really accurate... could explain why you are not seeing any readings.

A few ideas:
- not knowing what fish you have in the tank.... reduce the amount you are feeding by 1/2. Don't worry....they won't starve. IF you are feeding flake and pellets... stop and feed frozen for a while. I find that flakes and pellets can really add to excess nutrients.
-are you feeding your corals too? IF so.... stop or reduce significantly. Food like Reef Roids and Reef Chili can increase nutrients...
- when you do your water changes, are you using RODI? Are you using RODI for topoff? Do you measure TDS in your RODI? Depending on your tank and system... media needs to be changed to keep TDS low.
- when you do water changes, are you siphoning out any of the cyano? If not, suggest you do so. Do not recycle the water, rather discard it.
-manually remove as much GHA as you can prior to your water change too...
- I dont know what you are running by way of lighting.... but after you are done with the water change, reduce your lighting.... if you are at 12 hours.... take it down to 8 hours... Some corals may brown out if this is done for an extended time. See how they react...and how the GHA and Cyano reacts...
- If you are using t-5's were they new when you started your tank? If not, the life of T-5s is about 6 months...before they start to contribute to nuisance algae and cyano. I believe the thought is that the spectrum shifts a bit when they get old.
-not knowing what you have for cleanup crews... go to reefcleaners.com and find some that will attack cyano and GHA... Don't go too crazy... but a few turbos snails can do a lot of damage on GHA! Smaller snails and crabs can clean up rock and sand alike as well.

It is a good idea to have your LFS do some testing for you. Focus on Nitrates and Phosphates. BTW... I use Red Sea for Nitrate and Hanna for Phosphates.

Your tank is still really really young. As you have seen I am sure... it has gone through stages of uglies....and will for months to come. As your tank matures... so will some of these nuisance outbreaks.

Good Luck... I hope something here helps?

dansreef · May 8, 2019

A couple of things to think about, an existing outbreak of GHA and Cyano will artificially lower the tests you do for Nitrate and Phosphates potentially....and then the fact that API is not really accurate... could explain why you are not seeing any readings.

A few ideas:
- not knowing what fish you have in the tank.... reduce the amount you are feeding by 1/2. Don't worry....they won't starve. IF you are feeding flake and pellets... stop and feed frozen for a while. I find that flakes and pellets can really add to excess nutrients.
-are you feeding your corals too? IF so.... stop or reduce significantly. Food like Reef Roids and Reef Chili can increase nutrients...
- when you do your water changes, are you using RODI? Are you using RODI for topoff? Do you measure TDS in your RODI? Depending on your tank and system... media needs to be changed to keep TDS low.
- when you do water changes, are you siphoning out any of the cyano? If not, suggest you do so. Do not recycle the water, rather discard it.
-manually remove as much GHA as you can prior to your water change too...
- I dont know what you are running by way of lighting.... but after you are done with the water change, reduce your lighting.... if you are at 12 hours.... take it down to 8 hours... Some corals may brown out if this is done for an extended time. See how they react...and how the GHA and Cyano reacts...
- If you are using t-5's were they new when you started your tank? If not, the life of T-5s is about 6 months...before they start to contribute to nuisance algae and cyano. I believe the thought is that the spectrum shifts a bit when they get old.
-not knowing what you have for cleanup crews... go to reefcleaners.com and find some that will attack cyano and GHA... Don't go too crazy... but a few turbos snails can do a lot of damage on GHA! Smaller snails and crabs can clean up rock and sand alike as well.

It is a good idea to have your LFS do some testing for you. Focus on Nitrates and Phosphates. BTW... I use Red Sea for Nitrate and Hanna for Phosphates.

Your tank is still really really young. As you have seen I am sure... it has gone through stages of uglies....and will for months to come. As your tank matures... so will some of these nuisance outbreaks.

Good Luck... I hope something here helps?

isufishtank · May 8, 2019

dansreef said:
A couple of things to think about, an existing outbreak of GHA and Cyano will artificially lower the tests you do for Nitrate and Phosphates potentially....and then the fact that API is not really accurate... could explain why you are not seeing any readings.

A few ideas:
- not knowing what fish you have in the tank.... reduce the amount you are feeding by 1/2. Don't worry....they won't starve. IF you are feeding flake and pellets... stop and feed frozen for a while. I find that flakes and pellets can really add to excess nutrients.
-are you feeding your corals too? IF so.... stop or reduce significantly. Food like Reef Roids and Reef Chili can increase nutrients...
- when you do your water changes, are you using RODI? Are you using RODI for topoff? Do you measure TDS in your RODI? Depending on your tank and system... media needs to be changed to keep TDS low.
- when you do water changes, are you siphoning out any of the cyano? If not, suggest you do so. Do not recycle the water, rather discard it.
-manually remove as much GHA as you can prior to your water change too...
- I dont know what you are running by way of lighting.... but after you are done with the water change, reduce your lighting.... if you are at 12 hours.... take it down to 8 hours... Some corals may brown out if this is done for an extended time. See how they react...and how the GHA and Cyano reacts...
- If you are using t-5's were they new when you started your tank? If not, the life of T-5s is about 6 months...before they start to contribute to nuisance algae and cyano. I believe the thought is that the spectrum shifts a bit when they get old.
-not knowing what you have for cleanup crews... go to reefcleaners.com and find some that will attack cyano and GHA... Don't go too crazy... but a few turbos snails can do a lot of damage on GHA! Smaller snails and crabs can clean up rock and sand alike as well.

It is a good idea to have your LFS do some testing for you. Focus on Nitrates and Phosphates. BTW... I use Red Sea for Nitrate and Hanna for Phosphates.

Your tank is still really really young. As you have seen I am sure... it has gone through stages of uglies....and will for months to come. As your tank matures... so will some of these nuisance outbreaks.

Good Luck... I hope something here helps?

I've got a solid CUC (Margarita Snails, Astrea Snails) and am running LEDs. Ill try reducing lighting after the water change! I'm currently using bottled distilled water as I am in a dorm room and dont have space for an RODI system. I have not tested the TDS on the distilled water. I'm running carbon and purigen in the filter and only have 2 fish (a firefish and a flasher wrasse) in a 20g so I don't think i'm overstocked. I've stopped feeding ReefRoids recently to bring down the nutrients as well. I think reducing light and changing water is about as much as I can do right now until I get my water tested. Thanks for the advice!