Glass top under canopy.

[nsu7]

The LFS says I should still use a glass top over my tank under a canopy. I actually don't want to use the glass top, but do have some concerns about putting almost a thousand watts at 8 amps or so over open water. I want to get every bit of light under the water (getting a 210 (29" deep...)) and with a glass top on my 75 there's alot of reflection going on, esp when it gets dirty in between infrequent cleanings. Plus all that evaporation would help keep the tank cool during the hot months.


There will be 2 175 MH s, 4x96 PC, 2x40 NO, 2x55 PC. I suppose I could jb weld the fixtures screws for added security, but what about spray on all those bulbs, especially the MH... What do those of you with retrofit lighting under a canopy do to address these issues?

 

[TCTFish]

Using a glass top would not only protect your lights and lessen evaporation, but prevent the fish from jumping out.

 

[seaham358]

Using a glass top with a canopy is not needed. You want the top open for the evaporation, it helps keep the tank cooler. Both my tanks have a canopy and to control the jumping fish I have egg crate on the back on the canopy. It also cuts down on the light penetration to the lower level of the tank. I don't know anyone who uses a glass top, What type of lighting are you going to use?

 

[nsu7]

It also cuts down on the light penetration to the lower level of the tank.

Sorry to be confusing, but you're talking about a glass top, yes? I will have a 48" MHI / NO retrofit over 2/3ds (2x 175 watt and 2 40 watt NO). Then 4 x 96 PC over the entire length, and the 2 x 55 on 1/3rd opposite the MHI / NO fixture. (kind of an odd combination, but had to compensate for faulted planning, ie not being able to remove the center braces after all and upgrading tank depth twice during this planning stage...)

I guess I could use egg crate, but would the MH melt them, I'm thinking there will be at least 4-5 inches between them vertically. Would spray be a factor, maybe from where the water goes down the overflow?

 

[Hara]

That glass top will magnify the heat into the tank..you will have heating issues. It will also prevent a good gas exchange, you will end up with ph issues. Last, salt creep will soon cover it on a regular basis and also cut down on light penetration. As mentioned previously, egg crate will fix the fish issue.

 

[nsu7]

Thanks, will egg crate create any light restriction worthy of concern, I've noticed it casts shadows. Also what about salt creep on the bulbs, the canopy is probably 5 or so inches tall at least (on order) and I suppose I could keep water just high enough to go over the overflow. Am I being overly concerned about salt creep onto the bulbs? Any melting issue w/ egg crate / 175 watt MHI. Will have 2 67 cfm fans on each side of the canopy...

 

[Hara]

salt creep gets everywhere....pretty much a thing hobbiests just learn to deal with by wiping things down on a regular basis. My wraparound canopy is over 12 inches, I get creep up to the inside top edge. You will not have meltdown issues with eggcrate. Yes, it does cast shadows, but which is the lesser of the two evils in your opinion? sometimes we make trade offs. Eggcrate has a primary function of being a light diffuser, that is what it is sold as. I am not trying to sound like a smart alec, I have lost a few fish to carpet surfing. I do not use eggcrate on my big showtank and have quit buying fish that are known jumpers. Unfortunately, we can't have it all. (as soon as someone can figure out a way for me to do so, please let me know!)

 

[seaham358]

I dont have egg crate over the tank, I have it attached to the back open part of the canopy. The have a new plastic screen product at HD that is more flexable, I will be taking off the EC soon and use that.

 

[nsu7]

Hara: Thanks for the insight. I'll probably just experiement with both methods. I spoke with Kim Bryant at AHSupply Lighting and he favors using the tops, as "it reduces the green wavelength light" and "reduces condensation on the bulbs". He agreed that if I keep my 4 fans running overnight and minimize surface action it could be ok and agreed that lots of folks don't use tops w/ their retrofitted canopies all the time.

Seaham358: I see, I'll keep that in mind if I get any jumping species, may have to use it.

 

[melosu58]

You`ll probably going to have PH problems with glass tops.

 

[nsu7]

You think the problems would be the same or less with an open top sump with a turbo multi and a cora life 220 skimmers through 2 overflows?