should I use 70 watt or 150 watt HQI...

[RicGio]

I have a 90 gal , lighting was (4) T5's and (1) 250 watt HQI XM bulb. I liked the color, but the 250W seemed way too bright for my corals. The Monti's and birdnests near the top of the rockwere bleaching and my LPS's and Zoo's were not very happy either. I removed the 250W fixture and just ran the 4 T5's for a few months. Growth slacked way off and the corals just don't look as good.

I'm going to install a lower wattage HQI fixture, but I'm not sure what wattage to use? Will a 70 watter be enough? A 150 W too much? Any suggestions would be appreciated.

Also, I'm going to use a ballastwise ballast with an ushio 14K bulb. Anyone have any experience with this combo?

[Guygettnby]

i would think that a 250w on a 90g wouldnt be too much? i know that i would never put a 70w on that size tank. if you think the 250w is too much then go with the 150w.

but you can also switch the bulb out and put a 20k bulb in its place then use your T5's to suplement the 20k. just a thought.

[macreefster]

i cant imagine 250 watts would be too much for a 90. i have two 250w HQI's on my 70. i am thinking something other than the lighting was causing your problems with the corals. i used to run a 250w HQI on my 29g biocube with no problems! maybe check all your water parameters before changing your light. just my suggestion.

[RicGio]

I sent my water out and had it tested. all ok. Will the 20 k be too blue? Does the 20K have less PAR? I know I had the Monti and birdsnest about 6" deep in the tank and the light was about 6-8" above water level.