Lighting for clams?

[CHEAPREEF]

Would 2 175 watt MH be ok in a 75gal depth of 20". This would be for a maxima and a derasa. Or should i stick with the single 400watt i have now. The reason i ask is i am building a new hood and have 2 175watt MH and ballasts sitting doing nothing. This would also give me a better spread of light. What do you guys think?

Thanks
Clinton

[Delphinus]

Two bulbs will certainly give you a better spread..

As to whether 2-175's is better than 1-400 though ... I'm not sure.

I've had clams under 2-175's though, and they did seem to do OK under the lighting. It was issues other than lighting that I don't have those particular clams anymore.

If you have the ballasts anyways, why not go with all three? 2-175's flanking the 400. That'd be an INCREDIBLE setup. You could even consider maybe one of those Radium 20kK 400W's. Oh man ... I get goosebumps thinking about how good that'd look.

:D

[coldincanada]

I have two 175W 10K's flanking a 400W 65K with 3 110vho actinics on a 75 gal. This tank is dedicated to sps and clams. I am in the process of upgrading to 2 250W DE 10K's to replace the 175's. LOTS of light!

cic

[CHEAPREEF]

So run the 400 at 20k and the 175s at 10k. Would that be a good combo? Would i still need actinics or would this be ok on it's own? The reason i didn't really want to do it this way was the heat issue, also electricity cost. I worked it out the cost should only be $3-4 more a month so big deal, just the heat. Any other draw backs?

Thanks
Clinton

[FishGeek]

yah but can you afford to replace the bulbs every year. A 400w 20k bulb costs over $250 and 175w 10k bulbs are $200 a piece. That's $650 a year on bulbs alone plus electricity? Do you really need that much light for an 18" deep tank. I think it's over kill!! I say go with the 2 175w at 10k. Better spread of light and you wont melt your softies.

Simon.

[DJ88]

Simon,

Where are you getting your bulb's from? that is some really expensive prices IMO.

$189 for 400W 20000K
$129 for 175W 10000K at J&L.

[Delphinus]

So run the 400 at 20k and the 175s at 10k. Would that be a good combo? Would i still need actinics or would this be ok on it's own? The reason i didn't really want to do it this way was the heat issue, also electricity cost. I worked it out the cost should only be $3-4 more a month so big deal, just the heat. Any other draw backs?

Just the heat, and that will be a very serious concern in an enclosed hood (aka heat trap). But some fans will solve that pretty easily.

As for the lighting combo, I think it would be one of the best combos you can get. You wouldn't need actinics unless you wanted them there.

yah but can you afford to replace the bulbs every year. A 400w 20k bulb costs over $250 and 175w 10k bulbs are $200 a piece.

Well the bulb cost will be concern, true, but if you're paying $200 for a 10kK bulb you're paying too much by a factor of at least 2. MO prices are in the $100 range, and can be even less if you wait out for the sales (I think I paid $90ea for mine).

Yeah, it's an expensive hobby... (Why didn't somebody say so before!!!!!) :D

But let me just say this. If a person is not sure they can afford to replace the bulbs on a yearly basis, or pay the electricity bill, then shouldn't that pretty much be the deciding factor? I offer my suggestions as just that ... suggestions "to be taken under advisement." Only you can decide what's right for yourself! If you can afford it, great; if not, well hopefully something else will work out then (and there is always something else if you're creative, and take the time to understand the how's and why's).

PS. I have no idea how often a 20k bulb needs replacing. My first halides were those 14kK's or 12kK's or something and I found they were useless after 8 months. After 8 months the only things that grew while under those lights were hair algae and cyano... so there is that as food for thought...