glass top?

jb1

Member
i have a 75g that i'm setting up and was wondering is it bad to have a glass top on the tank to keep evap. down. i'm not going to have a canopy just a lighted hood with 6x65 pc's. i'm worried about the evap because of all the lights. the lights will be 6" off of the top of the water. will this cause my tank to not get enough oxygen. i will be using two h.o.b. filters that move around 330 gallons per hour. will this allow the water to oxygenate enough. will also have 4" dsb and 100 lbs of live rock, few fish, and some corals
thanks
 

nm reef

Active Member
Personally I would remove the glass covers. It helps disapate heat...provides better gas exchange...and your lights should be high enough to prevent problems.But...lots of folks do cover the top...so it boils down to a personal decision.
I'm curious about your 6x65 PC fixture...is it a retro or pre-assembled fixture? Provide additional info and/or a pic.

nmreef@cox.net
 

krowleey

Active Member
4 65w pc on a 75? shouldnt have to worry about dispating heat. in fact i lived in Tucson az with 4 96w pc on my 100 gallon and never even had to use the chiller.....
 

michaeltx

Moderator
the only thing you will have to watch is that every couple of months or so check the bulbs for salt build up and clean them off as needed.
I had 220 on my 50 and they were about 4 inches from the waterline and no glass covers. also glass will filter some of the light that you want in the tank so IMO leave em off LOL
Mike
 

krowleey

Active Member
also glass will filter some of the light that you want in the tank so IMO leave em off LOL
just UV light right? he aint gonna have sps in there with that kind of light. i would use the glass tops and have no salt build up and no fish jumping out.
 

michaeltx

Moderator
its something that I read that glass will filter out even some of the good light. HQI needs a glass UV sheild for that but on other bulbs it will demenish the light intensity and shatter and reflect it more than if they were removes water reflects some. but I cant remeber where I read it. from experience I started with my glass tops on after I removed them there was a noticeable difference in the light going into the tank. FWIW.
I wish I had a meter to see what the real difference in glass tops VS no glass tops.maybe someone has one that can test it out.
Mike
 

tangman99

Active Member
I removed my glass tops. Between the glass and the water on the underside, it filtered out a lot of the light. Looks better with the glass removed.
 

jb1

Member
no this not a retro kit, it is a manu. hood from a company. they can build anything you want
 

doodle1800

Active Member
What do you do about fish jumping out with no cover? I've had a jawfish and a clown commit suicide this year.
 

stumpdog

Member
jb1-
Is there a piece of flexi-glass or something that slides into the hood, which covers the lights? I have this on mine, wouldn't this prevent water from getting on the lights?
Jeremy
 

beaslbob

Well-Known Member
I think the glass top is fine assuming you have normal circulation. and also assuming the glass does not completely seal the top. Some holes are at the back or corners will allow air to circulate. Also, some type of cover may(is) necessary if fish decide to jump.
 

tlk

Member
I think it is a personal decision. I have 310w pc lights on my 75 and felt that the glass was trapping in too much heat. I have to top off the water a little more than I used to, but I also don't have to clean off the glass top (which by the way, needs to be kept very clean for the light to penetrate)
 

the claw

Active Member
I'm debating this myself. I don't want the glass to filter out too much light, and I have to clean it frequently. However, my Scott's Fairy Wrasse went carpet surfing last month, and my tank is like FOrt Knox. I really don't wnat anymore casualties.
 

reef fool

Active Member
The main problem with glass top IME is
1) Keeps heat in or makes it worse
2) lessens gas exchange
3) when salt accumulates, can block beneficial light (need to keep it clean)
 
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