Zoas losing Color

[SubParReefer]

Hi all,

I bought my first two coral frags about 3 weeks ago, one utter chaos and one Rasta zoa colony. They looked awesome under blue lights and even white when I first bought them but now some polyps are starting to lose their colour.

I’m running the stock Fluval Evo LED which I believe has a PAR reading of around 95 on the sand bed which is where the Zoas are placed. The rastas are starting to look slightly grey(?) in the centres of some polyps and the utter chaos’ tentacles don’t have a lot of the fluorescent orange they’re famous for.

Could this be due to too much/too little light or an imbalance of nutrients?

Parameters:
Temp 25.5C
Salinity 1.025 sg
Nitrates 0-3ppm (API test kits are difficult)
Phosphates 0ppm

I’m currently battling cyano in the tank which I think is cause of low nutrients, hopefully getting on top of it finally.

Photos attached:

 

[PlumbTuckered]

Systems that include lights rarely provide enough light to support corals. Raising corals are about light and flow.

Try moving them around the tank. Raise them up higher so they are closer to the light. Also, if you are relying on the return pump to provide all your flow, it will be insufficient. You will need to add power heads.

 

[shakacuz]

low po4 could result in color loss/"bleaching", but also take into consideration that corals look a certain way under blue lights than they do under white. try raising the plugs a bit higher so they could get a bit more light, and focus on raising your nutrients up a bit.

 

[SubParReefer]

Thanks both, I’m feeding more now to try and raise nutrients but I think the cyano is absorbing them all. Currently fighting the war!

I’ll try to raise them a little higher in the tank. I have a Seneye reef so I can measure PAR levels in different areas, do you have a recommended range for PAR?