White spots (not pests)

Lousybreed · Jan 31, 2019

Hi once in a while some of my corals get white patches on the undersides. I think it’s when I have low nitrates in my system. Does anyone else have this problem? It’s like they appear quickly but take a while to heal. Any ideas? There is one on my ORA frogskin if you look closely. Again I do not have pests in the tank.

ndrwater · Jan 31, 2019

Could be a flow issue. SPS LOVE. flow. I have had issues similar in the past and always solved the problem by thinning things out a bit.. allowing for growth is one of the hardest things SPS keepers have to learn. When corals are happy, they grow like weeds. The problem then becomes that they end up choking each other's flow to a point where they start receding/dying off in low flow areas.

Lousybreed · Feb 1, 2019

This is a good point. Right now I am at 65-85 turnover rate. I have great random flow with my Sea swirl return, dual gyre 250’s, two Jebao SOW-15’s and two Jebao SOW-8’s. I am going to look further at my flow as this is a good point and something I need to make sure is good. I have more wavemakers I can put in the system.

Lousybreed · Feb 1, 2019

My tank is a 250 gallon Deep Dimension (5’x3’x30” tall)

29bonsaireef · Feb 1, 2019

That looks like more of a lighting issue then flow, imo. Could be a mix of things, but that green coral looks heavily shaded on the undersides.

jda · Feb 1, 2019

Is it just on the undersides, or are there white spots on the top too? If just on the bottom, then look lights. LEDs and super-small-reflector MH are horrible with this.

I think that you have enough flow not to worry about that.

Edit: it is probably not low nitrates by themselves. I have .1 which you need an ICP test to detect and I don't get any of this. Ocean is lower than that. However, if they were already on the brink, then this might finish them off.

Lousybreed · Feb 1, 2019

I have 13” by 13” MH reflectors, 4 T-5 bulbs, and two reefbrite XHO 4’ strips. This tank is literally bathed in 300-400par almost everywhere. But these white spots happened quick and now no more. I did have a Jedi mind trick that went white on top. I pulled all the cheato and I didn’t lose it. It has stabilized and is coming back.

Lousybreed · Feb 1, 2019

I am open to looking into all options. Alk 8.0, Ca 440, Mg 1390

jda · Feb 1, 2019

Refractometer calibrated?

What about nightime pests like bad urchin or coral eating snail?

Probably not the lights.

Running any organic carbon or GFO?

Lousybreed · Feb 2, 2019

jda said:
Refractometer calibrated?

What about nightime pests like bad urchin or coral eating snail?

Probably not the lights.

Running any organic carbon or GFO?

Yes on the refractometer. I actually have two. 1.026. No urchins. What snails could eat coral. You have me interested. I will do some research too. Thanks!

Graffiti Spot · Feb 2, 2019

A closeup on the damage would help a lot in trying to determine what the causes could be. A white patch like that could be a number of things.

jda · Feb 2, 2019

Whelks can get a taste for coral. They leave damaged spots on corals as they move across the tank.

I don't imagine that your building blocks are at poison levels, or anything? Like N over 50 and P over 1.0?

Lousybreed · Feb 3, 2019

Jda, no. Nitrates at 1.0-0.75 ppm and PO4 at 0.05-0.03ppm. All via ICP analysis. I do have whelks. My tanks are heavily feed and I would asssume that they have plenty to eat but you never know.