What factors into SPS polyp extention?

I am new to SPS and while keeping them alive and seeing growth doesn't present a problem, PE does.....and no, I don't need to talk to my doctor

My birdsnest and stylophora are fine, but my acros and milles do not have any PE at all.

Is it lighting, flow, water conditions...which I know is the case...but what is most important?

I have a 215 gallon with a 12 bulb Aquaticlife T5 light. SPS are in the top third of my tank.

I have two Korala 12v wavemakers...i believe 2500 GPH.

I don't have my specific params today, but in the past nitrites were 0, nitrates - trace, salinity 1.025, PH 8.2.

 

flow, available food, and lighting affect PE(assuming all tank parameters are good). More indirect flow, more food, and less light all equal more PE. could you post some pictures of the corals?

 

I'll get some pics later tonight.

You said less light...did you mean more light?

I would think food being the lowest just for the fact that my friend never feeds his corals and has crazy PE.

You also say indirect flow...so nothing pointing right at them I assume?

 

Yes,
lower light effects PE because the coral has to expand to capture more light

more food effects PE because obviously there is more food in the water, so the coral tries to increase its chances of catching it

anything too strong pointed at the coral can actually stress it out.

 

It depends on the Acropora. Millepora typically does well and will get real fuzzy with strong waterflow and high light. If you try to do the same for plana you will get some bad results.

My best suggestion would be to properly identify the corals that are doing bad and then do some research to what would be the best husbandry for each one.

 

Depends on the coral. I wouldn't necessarily say any of this about a millepora sp. They love lots of light, water flow, too much food in the water can cause too much PO4 and NO3.

 

There is lots of light and then there is too much light. I can push too much light and flow for any millepora. It's all relative. And there is no such thing as too much food, that's separate of the waste that can be handled with filtration (more than the average hobbyist)


With leds in particular, it's becoming easier and more common to over light. Or a 1000w MH, most of us can't use this bulb because it's way to powerful. Also, if you are in direct laminar flow or just too close to say a vortech mp60, there is just too much flow. (I have this problem in a couple spots in my tank)

 

Thanks for the advice. I'll check the flow and light on those guys and see if they need new spots.

 

I have provided too much light with my T5HO unit.

I have noticed more PE with very low nutrient levels in the tank.