Too much light?

[stewie24]

Current display tank (have bigger sump/fuge attached) is 10 gallons.
Right now there's a jbj k-2 viper 70 watt w/ the stock 14k bulb over the tank.
The outter edges of the tank are pretty shaded so I was pondering the idea of changing it to this:
Buying a 2x 70 watt retro. Building a canopy w/ fans. Placing both lights over the tank in the canopy beside each other (with a little space between them) as to lighten the whole tank.
I was thinking of going w/ 2 10k bulbs and then putting a 2x either 13 or 18 watt actintics in the hood.
My corals include:
Huge hammer (17 heads) - takes up whole right side of the tank.
green digitia up top
various zoos - mostly in the upper 1/2 of tank
pink anthella - bottom of tank
real nice red/green brain - on sand
10 heads of candy cane - on sand and center of tank
green hairy shroom - left bottom of tank
yellow toadstool - bottom and left.

1. You guys think that 140 watts of mh light (2x 70 watters) (wouldn't be near as bright as a single 150 watt because 70 watters are not as even as 1/2 bright as a 150 IMO) and 26-36 watts of actintic would be too much for my tank and what corals I have?
I evap about 1/2 gallon a day for the whole setup (10 display overflowing into a 20 long sump/fuge)
2. Would I evap that much more with another 70 watt added?
My temps stay constant around 81 degrees.
3. Would my temps raise a bit more w/ another 70 watt added? Right now the light is about 5 inches from the surface. I'm thinking with fans it shouldn't get any hotter and it might even make it a little bit cooler.

Thanks
Stewie

[Jordan55]

Just thinking it over slighty, metal halides and canopies usually do not go well together. You are almost certain to get heat issues unless you are lucky and thinking about the canopy build itself to design the flow of air out well enough.

Also, 70 watts seems fine to me on a 10 gallon. As long as you are noticing any decay in your corals and your water parameters being okay ( basically your last thought is bad lighting) then why upgrade? It sounds like the corals you have are fine with 70 watts of MH.

Is your MH fixture resting on the tank or is suspended? How low or high from the tank? Try raising it a tad bit to get light on all sides of the tank?

Just a few thoughts.

[stewie24]

Thats the problem i'm having...
Its a clamp on fixture (with a very poor reflector at that).
I've tried raising and lowering the light to no avail and when I raise it, the tank just gets dimmer.
Perhaps its just the bulb or the reflector itself.
I could rig up a canopy to be room temp (even with MH's running.)
I have access to some real nice comair rotron fans that run on 110 and really move some air.
1 fan on 1 side blowing air in and 1 fan on the other side from exhaust (it'd at least keep alot of air moving over the fixtures)
The water quality is fine, the corals are healty - the major problem seems to be the lack of lighting on the sides of the tank - my hammer is on the right side of the tank, and the part thats closest to the center (where the light is) is doing real well, and the heads towards the glass on the right seem to be reaching for more light and aren't as open as much(its not a flow thing either).

perhaps others using 70 watt fixtures besides the viper can chime in here. I read somewhere someone was using a 70 watt fixture over a 15 gallon or so tank and thought the light was real bright.

Like i said, since I've never seen or used a different 70 watt fixture, Im not sure how bright they are really supposed to be. I'm think perhaps a funky bulb (its bright to look at -don't get me wrong, just doesn't light up the tank like I thought it would)or a very poor reflector (its like a hammer tone thats not even shaped like its reflecting light).

Stewie

[stewie24]

One other thing I could do is buy the retro and instead of using 10k bulbs, just buy 2 70 watt ushio 20k bulbs (never heard of anyone using them but I found a place that sells them) and forget about the actintic supps.
It wouldn't be as bright then, but at least i'd have the shaded areas covered.
Stewie

[AIMFish]

Wouldn't a 150w HQI be less considerably expensive than 2 70w? :confused: :eek: Oh and it sounds nice already, where are the pics?!!

[stewie24]

Yeah Yeah.. Ill get on w/ the pics :D
Well tomorrow that is... going to work now, and i won't be back till tonight when the MH's are off..
Actually i can get 2 70 watt retros (bulbs, ballast, uv shield, reflector) for a little over 200.00
The 150 watt viper is 199, but since i think the vipers reflector quality if poor, i'm not going w/ the viper.
Thanks
Stewie