help lighting ?

[chadcc]

my tank is 20"L X 18"W X 25" D my light is 250W hqi 20k i have frogspawn zoanthid ric the ? is how hight should my light be from top i tested the water and thats all good but some of my zoanthid wont open fully

 

[vietcu]

If the zoos won't open fully its not because of the lights. You might have too much flow shooting at them. Their skirt shouldn't sway back and forth that much. In my tank I found that the less flow I have shooting at my zoos and lps, the more they open. As far as lighting is concerned, I have mine about 8" from the top of the water line.

 

[Aadler]

id put that light 10-15 inches over your tank at least, and put the listed corals in the bottom third of the tank.

 

[TheGrog]

8-12" above water line for light placement IMHO.

As for why they are not opening, I agree with vietcu in that it is not the light but water flow. You either have too much directly on them or not enough. Zoos don't need tons of light....and most do better deeper in the tank with MH lighting.

Check your water flow and if necessary, move them lower in the tank in an area with good, but not too strong, water flow.

 

[chadcc]

how long should i run it

 

[the budman]

i have 230 watts of pc over my 40 long. its only 3 inches off the tank but its not mh