Bali Green Slimer Going Through STN and Browning

[NickNiz]

Hello all!

I have a BGS frag that isn't doing to well... As the title says, it is browning and going through what looks like STN from the bottom up.

And here is placement in the tank...

Polyps aren't extending that much either.

Here's some other info...
Tank: JBJ 28g Nano Cube
Lighting: AI Prime HD with the following schedule.

Flow: Waveline WavePuck II, almost directly pointed at it, set to 40% with a cycle of 2s on 1s off. Additional flow comes from two filter pumps that are part of the tank.

Water Parameters:
Alk: 10.1 (Salifert)
Ca: 440 (Salifert)
Mag: 1450 (Salifert)
Nitrates: 5-10 (API)
Phosphates: 1.5ppm (API)
Salinity: 1.025 (Red Sea Refract)

My guess would be phosphates, but do you think there's another contributor? If it is phosphates, how should I bring them down? I do 10% weekly WC with RODI water as it is... and I can't exactly add a GFO reactor to this tank. Could I get a bag of it and throw it in the back?

 

[markalot]

I don't believe the API Phosphate test, but if it's that high I would expect browning but not death. KH is high for Acros, they do better at NSW levels, like 7 to 8. If you are using a high KH salt then odds are you are swinging KH a lot and this will kill acros, they need stability in every parameter to get healthy and stay healthy. This includes KH, PO4, lighting, and to some extent calcium and Nitrate.

So, if you are going to lower PO4, if it's high, you will need to do it slowly. GFO can easily kill corals if you use too much. You also want to know your tank chemistry and lock KH into one value and hold it there with no swings.

 

[XNavyDiver]

I agree with @markalot. I was thinking a possible dKH swing.

 

[Bdrake]

Another possibility is chemical warfare. Your green slimer is awfully close to those zoas

 

[NickNiz]

I don't believe the API Phosphate test, but if it's that high I would expect browning but not death. KH is high for Acros, they do better at NSW levels, like 7 to 8. If you are using a high KH salt then odds are you are swinging KH a lot and this will kill acros, they need stability in every parameter to get healthy and stay healthy. This includes KH, PO4, lighting, and to some extent calcium and Nitrate.

So, if you are going to lower PO4, if it's high, you will need to do it slowly. GFO can easily kill corals if you use too much. You also want to know your tank chemistry and lock KH into one value and hold it there with no swings.

Thanks for the answer! I actually do normally keep KH relatively low at 7-9 so I was a bit surprised when I tested at 10.2, but figured it was in an acceptable range... I’m not really sure how it rose so much either. I use Red Sea salt (not coral pro) which I know is a little lower across the board, and then I dose with Reef Foundation until desired levels are reached. Tests/supplementation is normally done twice a week, but I was especially busy last week and didn’t do it. Is there any other way it would have increased?

 

[NickNiz]

Also, how much GFO do you recommend to start with? I’m using Two Little Fishies PhosBan, and they recommend 1g/1gal of aquarium water.

 

[markalot]

Also, how much GFO do you recommend to start with? I’m using Two Little Fishies PhosBan, and they recommend 1g/1gal of aquarium water.

I don't like GFO so i can't recommend how much to use.

Reef Foundation is a 2 part (3 parts) that has a calcium part, an alkalinity part, and I guess the 3rd is Mg. You should not dose unless the tank needs it. A spike to 10KH is usually fatal to acros, especailly new frags. Don't be shocked if you lose it. Sometimes fragging and supergluing to a new plug, making sure to superglue over any dead area, can save it, but it will be a long road.

If you plan to keep acros your KH has to be locked in. Not 7 to 9, 7 to 7.25. Any KH will do, 7 to 10, but whatever is chosen must be kept rock solid stable. Typically this is with a doser. Acros are a pain in the butt to start with, but get easier once you get used to and find ways to keep the tank stable.