PC lights question

[amandadee]

Hey, I'm probably getting a little ahead of myself here, but I hope to eventually upgrade to pc lighting and try my hand at some of the easier invertebrates. Since I'm used to my *blush* Perfecto hood with handy flip-top lid, I don't understand how the pc units with legs that seem to hover over the tank "keep the fish in." Do you use a separate glass top between the water and the light? And what is the fan for, to cool the bulbs or the water surface? Because if the latter, that blows my whole glass-top theory.
Maybe the jumping fish idea is not as major a concern as I'm thinking? But my snails wander all over the underside of the hood I've got, and I can just see them sneaking out for me to step on in my bare feet in the morning! Anyone else have this problem? :notsure:

 

[dmc888]

Yeah they sell glass top kits.
Comes with 2 pieces of glass,hinge,handle,and plastic trim for the rear.
Most fish stores should have them.
Most pcs have fans built in to keep the ballasts and bulbs cooler.
Pcs don't make much heat so it shouldn't bother your tank temp.

 

[vlondi]

You can get glass panels to put on the tank itself and have the light above it. Some people go this way although I think the glass can get condensation and eventually salt buildup on it.
I believe that those who need it on these boards get what is called "eggcrate". This is basically a "sheet" of metal or plastic 1/2 inch squares that allow a lot of light through but block jumping fish from getting out. One of the board members has a pretty good picture of what eggcrate looks like, perhaps he will post.
You can get it at hardware stores like Home Depot or Lowes and they will probably cut it to your needs.

 

[doboy]

I have an Orbit 260 watt PC. There are two actinic bulbs and two "daylight bulbs". The fan is for cooling, and only runs when the "daylight" bulbs are on.
The legs are removable, and the whole fixture can rest on a glass top. This particular maker says to never have the fixture exposed to the water -- although it has a clear shield.
You can use the legs, which are adjustable. They slide, and can be positioned to rest on the top sides of your frame. I use the legs, and a glass top because I have some "jumpers". But, I suppose you could use egg crate if you wanted the tank to remain open.
I also built a hood. But, because of the PC fixture, I had to leave the sides open, or else the fan wouldn't work. I did talk to the manufacturer, and they said my hood design was fine.
Hope that helps.
Jim

 

[dmc888]

I forgot to mention i have coralifes on both my 29 130w and my 55 260w.
Very happy with them.

 

[22caddy]

Don't put a glass top on. It traps heat and lowers the gas exchange needed in the water.

 

[amandadee]

That's an interesting point. Like I said, I already have the plastic hood on, and haven't experienced any heat or gas exchange problems, so I'm guessing I could expect about the same with a glass top as long as there's enough room between the water surface and the glass, as well as a little open space for ventilation.
Does the glass top cover the entire top, or does it give you room along the back for all your filters and heaters and junk?
I'm thinking eggcrate is the type of stuff they put on elevator ceilings to diffuse the light, right? An interesting idea, but doesn't it look strange, light the top of an elevator? I'd hate to confuse my fish: "Aren't we ever going to get to the top?" Hehe, sorry.
dmc888, what do you keep in your 130w 29g? That sounds like just what I'm heading towards.
Amanda :thinking:

 

[dmc888]

Well the glass tops have a plastic piece on the rear part that you can trim.
It goes all along the rear so you can cut it to your needs.
Pretty much covers the whole top.
Well in my 29 i have 2 true percs, a jawfish, and a valentini puffer with some fake corals.
Pretty much a fish only tank.
I plan on putting an anemone in there eventually.
A drawback on the eggcrate would be more water evaporation.
Plus i would only do that with a canopy to cover it.

 

[dskidmore]

Originally posted by 22CADDY
Don't put a glass top on. It traps heat and lowers the gas exchange needed in the water.
If you have a protien skimmer, you shouldn't be short on gas exchange. As far as heat goes, you really have to see if releasing heat or reducing evaporation is more important in your case.