how long to run ushio 20k 250watt??

[rsantangelo3@co]

im going to a 30 cube tank and running a single ended ushio 20k 250watt as my only source and i have zooanthids and sps from top to bottom. how long should the photoperiod be ran being the only light source and wekaer par being 20k. Also will some acros not actually grow under a 20k? I have heard this before- thanks in advance guys!

 

[Chyendra]

just curious how tall your 30 gallon is? I just upgraded my 250w 20k bulb to a pheonix 14k hopeing to get some better results.(the 20 might have been old so that could have been part of the problem) My 45 gallon tank is 18" tall. I keep my lights on 7 hours. I would say anywhere between 5-9hr is best.

 

[allsps40]

I run a single 250w only has well. I run it for 8 hours.

 

[rsantangelo3@co]

20k? find less growth?