H2O2 and corals?

[Angelwolf21203]

I recently had an issue with an outbreak of GHA. I ended up having to pull out every rock and coral, and even my fish, and I did a 40% water change. I pulled as much of the algae off the rocks as I could and sprayed then generously with hydrogen peroxide. But, the rocks with corals attached, were a little more challenging, because I was trying to keep the coral itself in the water. And though I did use the H2O2, I was much more reserved and gentle. So the GHA is back on those rocks. No where else. So what I want to know is I pull those rocks back out to treat them again, and if the H2O2 hours my corals, are they going to suffer? There is also some growing in the rock my anenome is attached to. The corals involved would be my green nepenthe tree, some zoas, a few very large green hairy mushrooms, and my BTA. All softies.

PS, H2O2 kills bristle worms really quickly and effectively! LOL!

 

[andrewey]

I wouldn't advise spraying H202 on corals. In certain concentrations they can tolerate it, but there's a small margin between tolerance and coral death. Instead, try and pull the rock and target the GHA with a syringe, dropper, or toothbrush dipped in peroxide.

 

[Angelwolf21203]

I wouldn't advise spraying H202 on corals. In certain concentrations they can tolerate it, but there's a small margin between tolerance and coral death. Instead, try and pull the rock and target the GHA with a syringe, dropper, or toothbrush dipped in peroxide.

Ok. I like the tooth brush idea, but I have read that using one will actually spread the algae even more. Do you know if there is any truth to that?

 

[Angelwolf21203]

Forgot to attach pics, earlier.

 

[James M]

I would start with manually removing it with water changes.

 

[andrewey]

So if you use the toothbrush in the water, it will knock the algae off the rock, "spreading it". However, if you were to use the tootbrush as a surface to apply hydrogen peroxide, any algae you dislodge would still be removed because in all cases of hydrogen peroxide and green algae, you should rinse the piece in sacraficial saltwater before it enters the tank.

I do agree with @James M that it would be best to start with hand plucking the algae off the rock with a siphon in your other hand (going into your water change or a filter sock and reusing the water). If you have a lot of hair algae, killing all that you pictured with peroxide will release a lot of those nutrients back into the tank, fueling more hair algae long term.

 

[Angelwolf21203]

I already went through pulling it by hand, which was not hard, just time consuming, and that's the rest of the rock in my tank. So I cleared A TON already. But I took everything out of the tank. I can't expose the corals to the air, so I did the best I could with those rocks while sitting in my living room leaning over a storage bin with water in it and removed all that I could, then gently sprayed while being careful to avoid the corals. But what I am apprehensive about, is when I do this again, and while I'm applying the H2O2 to the rock, a little bit of it comes into contact with the coral...am I going to loose the coral? I had those rocks completely picked clean, but obviously, I didn't get enough peroxide onto them (or maybe it washed away?). Here is a "before" to show you just how bad it was!