MH close to water???

[Jimbob]

How many of you fellow reefers out there use MH lighting and have the bulbs mounted relatively close to the water. I'm thinking of going MH, but my problem is that the bulbs will only be about 3.5" above the water level.

I can mount plenty of fans to keep it cool, but what are everyone's thoughts opn mounting MH so close to the water?

-Jimbob:eek1:

[colemanitis]

3.5" is too close IMHO. I would be extremely concerned about water splashing the bulbs and cracking them.

[Jimbob]

Help me out guys... I'm hoping to find some people that have kept MH's in close proximity to the water successfully for a while... I could lay a sheet of glass over the access hole to the tank to eliminate the splashing possibilities.

-Jimbob

[colemanitis]

Originally posted by Jimbob
I could lay a sheet of glass over the access hole to the tank to eliminate the splashing possibilities.You won't want to cover your tank completely. This will lead to raised water temps and a reduction in evaporation/gas exchange. What MH's are you looking at getting? Also, is your 20g a tall, or a long?

[moonpod]

If you do that Jimbob, I'd highly recommend using DE pendants that have glass shields built in already. Then your big issue will be heat, not splash. You can mount the pendant to your canopy, but it may lower the fixture even more.....

[Jimbob]

Colemanitis, my 20G is a 20H. It is 24X12.5x18 (I think it's 18" high, but I'm positive on the 24x12.5 footprint. If I get a chance, I'll try to throw some pics of it up later tonight. I have a 110W (2x55) Helios PC fixture on it right now, and it has treated me fairly well, although the xenia isn't too happy. The various zoos and shrooms, plus one poylthoa have all done remarkably well under that PC set-up. I was asking on the MH's because I would prefer to go MH over the Tenecor 85G, but am limited in space.

Also, I was looking at either a 2x175 watt MH retro kit to be augmented with 2 x 36" NO actinics or 2 x 96W PC Actinics for the 85G. the 3.5" clearance made me a little hesitant, so I wanted to see if anyone else has successfully done this. I would also consider going with a 2x150 watt HQI MH retro.

Third choice is T5's... I poseted another thread asking for some time-lapse photo's of systems under T5's so I can see how well things do long-term under the T5 set-ups.

Fourth choice will be to go with an IceCap660 and 95W VHO's.

Last choice and not really an option in my book is PC's. Although they are doing OK on my 20G, I really don't like the PC's that well.

-Jimbob

[Jimbob]

Colemanitis, my 20G is a 20H. It is 24X12.5x18 (I think it's 18" high, but I'm positive on the 24x12.5 footprint. If I get a chance, I'll try to throw some pics of it up later tonight. I have a 110W (2x55) Helios PC fixture on it right now, and it has treated me fairly well, although the xenia isn't too happy. The various zoos and shrooms, plus one poylthoa have all done remarkably well under that PC set-up. I was asking on the MH's because I would prefer to go MH over the Tenecor 85G, but am limited in space.

[Jimbob]

Anyone else have any experience or thoughts here?

[pamela-troy]

i have a 50gal with 2-250 watt MH's about 2" above the water. i ahve had this set up for about 2yrs now. i do have 2 sheets of glass underneeth them. i do have to clean the glass about once a week but my corals love it. if you have any question pm me.

Troy

[Entropy]

I have mine four inches above the water with only eggcrate in between. I have had them setup exactly one day :rolleyes: so I am not much help I guess....

The way I look at it though, there is not much in the tank that will splash other than the fish and I am hoping (betting) that if one tries to jump or splash that the event will happen somewhere other than the two areas below the MH's.

[Entropy]

Just had a interesting though... You could cover the top of the tank with eggcrate and then just slip a piece of really thin glass or maybe acrylic on top of the glass between the bulb and eggcrate, but only big enough to cover the area under the bulb (maybe 8"x8") and leave the rest open. That should minimize any splash issues... Hmm I may do that myself. Cleaning would be easy too, just slip the piece out after the MH's bulbs are off so there is no danger.

[Loserland]

I keep ,mine 6" from the water. I have glass under the bulbs only and run a chiller which is a must to avoid 7-10 temp swings. Loss about a gallon a day of water.

[JPMagyar]

I had a Tenecor 50 gal with 2 x 150 watt HQI pendants and 2 x 18 watt MiniMight PCs only 3 to 4 inches above the water. No problems except cleaning the glass cover on the pendants every week or so. . .


Hope that helps!


Joe