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View Full Version : Brand new MH...and is my top about to break???


Aynesa
10/05/2008, 06:38 PM
Hello all

I broke down and got an MH hood today, since if you've been watching my coral thread, I was given four corals. My LFS was going out of business, and had an awesome 150w MH hood for 200 I snapped up. I set it up above my 100 gal, but the glass top is getting really, really hot. I have it mounted on the mounting brackets that came with it, it holds it about 3-4 inches above the tank. The glass is getting hot to the touch, and I'm worried about a fish splashing and shattering it... am I being paranoid?

J.russell
10/05/2008, 06:45 PM
You have a lid on the tank with the MH 3-4" above the lid?

Aynesa
10/05/2008, 06:47 PM
Correct. The lid is thick glass, with the MH about 3-4 inches above the glass.

J.russell
10/05/2008, 06:50 PM
I would take the glass off. Any reason you have the lid on there?

Aynesa
10/05/2008, 06:51 PM
Suicidal fish, to slow evaporation, because I'm not concerned with oxygen contact with the water between a huge air pump and my sump, it's always been there, and because the legs of the hood won't reach the edges, so if I take the glass off it goes into the water. :)

Aynesa
10/05/2008, 07:00 PM
http://www.current-usa.com/sunpod.html

here's the light, in 24"

JR's Reef
10/05/2008, 07:03 PM
You prob will have to take them off due to heat issue with MHs. I would find or make something for it to sit on and due away with the glass tops. Just my .02

Aynesa
10/05/2008, 07:06 PM
Suggestions on what? Eggcrate would melt, plastic would melt, don't know about acrylic, I really *need* this top covered (I've already lost some eels and fish to accidentally leaving the top open or standard escapes from the rear, including a snowflake eel 2 days ago). So, if glass won't work, what will? Can I just not go MH?

J.russell
10/05/2008, 07:14 PM
How deep is the tank and what light demanding corals do you have in it?

Can you hang the light and raise it higher up?

Jefe12234
10/05/2008, 07:14 PM
I would mount a small fan blowing between the fixture and glass top. It should keep your tank a bit cooler as well.

Aynesa
10/05/2008, 07:16 PM
I've got a silver fan around here somewhere I've been looking for. My tank being cool isn't an issue. CL-650 chiller :) My tank NEVER spikes above 79 degrees. EVER. I'm mostly worried about the glass breaking and spilling two very expensive fixtures into my tank.

Aynesa
10/05/2008, 07:41 PM
So far my corals extend to a couple of colts, an open Brain, some Green Star Polyps, and a few macroalgae. That's all. I'm wanting to move into SPS someday though, and this fixture was just too sweet a deal to pass up...

Aynesa
10/05/2008, 07:43 PM
Sorry russel, missed the other half of your post.

I CAN hang it if push comes to shove, but haven't yet because I don't have the hardware here and it's sunday night so all the places that have such hardware or closed.

the tank is 31 inches deep. The corals right now are at roughly the low-halfway point.

J.russell
10/05/2008, 07:51 PM
Ehh... might not be a good idea to hang it higher then :( Sorry

Aynesa
10/05/2008, 07:51 PM
My real question here is will this heat break the glass? I think we're getting a bit sidetracked on the question. The glass is getting hot, but i can still fairly comfortably lay my hand on it and rest it there. It's been turned on for at least 3 hours. Do I have anything to worry about?

J.russell
10/05/2008, 07:57 PM
Kinda hard to say. I dont have any firsthand experience with a situation like this. I would think after 3 hours the light is as hot as its going to get so if the glass isnt burning your hand yet, I think you'll be ok :)

Aynesa
10/05/2008, 08:01 PM
Phew! No, no burning hand. IT's hot when I rest it on the glass, but that's to be expected. My real fear is a fish splashing water up. Maybe I'll pull out a thermometer and test the actual temperature of the glass. I have a meat thermometer that should get me relatively close.... my digital thermometer is sorta buried. My chiller has a temperature display, so I don't need it and it just got sorta....lostish. I know where it is, but it's really hard to access.

It's not burning my hands, I GUESSTIMATE 110-120 degrees on the actual glass, and my water is 79.

kgross
10/05/2008, 09:07 PM
It could break the glass but I don't think it will. Can you make a 1 to 1.5 inch spacer to put under the legs to pick up the lights just a little higher. The biggest danger as you said is the hot glass and then water being splashed up on it. But if you could go a little bit higher and put the fan across it, I don't think you will have any problems with the glass breaking. But I would suggest you use something other than the glass tops to support your light....

Kim

Aynesa
10/05/2008, 10:43 PM
Thanks. It's now been on 6 hours, the glass still has plenty of room to expand, and even the rubber or silicone holding the glass hinges together isn't melted or melting. The meat thermometer said '140' and is holding about there, but I don't think it's anywhere near that hot. As soon as I can I'm going to try to break out the digital thermometer and see what it says. I'm pretty confident it won't break the glass now, though only time will really tell. Water is splashing up on it near constantly, too. I glanced when I took another look, so, I'm going to just cross my fingers for now. IF something changes I'll let ya'll know.

Thanks!