Explain this 'glass top' thing to me.

[verucaproduce]

I am looking into getting a glass top for my 29 gallon tank. It has a single strip light on it now (20w) and I am not in any position to spend lots of $$$ on a CF, so I have to work with what I have. I am wondering a few things:

First of all I have read many posts about people adding random strip lights and/or shop lights to their tanks. Are they putting these light right on top of the glass? Can you place a light on top of the hinged section or would water end up condensing on that bulb? (Can you tell I have never seen a glass top in person) 8O

Also, do you lose a lot of light through the glass top?

I have seen glass tops for single and or double strip lights. Is one better than the other if I were to keep the existing light and try to add something I rig up?

Any other pros/cons to having glass instead of plastic?

 

[verucaproduce]

One more question. Would I be able to get an incandescent fixture and replace it with those little screw in fluorescents?

 

[QTOFFER]

Glass tops are really nothing more than two pieces of glass, sized to fit the tank top snugly, connected by a flexible plastic hinge. I have no idea why they're so expensive - I mean, they're just made of glass. I once tried making my own 10 gal top out of plexiglas with disappointing results. Plastic doesn't work well because the heat from the aquarium and the light tends to soften it.

If you place any type of light on top of the tank, you must have a piece of glass between it and the water for reasons of electrical safety. The glass transmits light very well, but once a month, I have to clean off algae and deposits with warm water. Putting a fixture on top of the hinged region is OK, but might be a pain when you need access to the tank.

I don't see why you can't use a regular undercounter fluorescent fixture and save some money. You just need to find one that spans the length of the tank and will accommodate enough wattage for you.

I don't like the idea of using an incandescent fixture with a screw-in fluorescent because I don't think the light would be distributed across the length of the tank as well as a fluorescent tube fixture.

 

[Toirtis]

I don't like the idea of using an incandescent fixture with a screw-in fluorescent because I don't think the light would be distributed across the length of the tank as well as a fluorescent tube fixture.

Agreed...this only works for smaller (15g>) tanks.

 

[malkore]

I also agree. 15g tall tanks work well with a dual incandescent fixture for a 10gallon (same footprint as 15tall) but with PC screw-ins. You can even keep plants with those. Crypts and java fern will do fairly well.

 

[TomK2]

wouldnt incandescent bulbs throw off more heat too?

 

[youronlysin]

I have two screw in PC daylight bulbs over my 15T. They are rated at 20 watts each @ 6700K. They DO produce some heat, infact, the inside of the hood gets quite warm, but they are much cooler burning than incandescent bulbs. This does not cause any problems with my water temperature though...that may be because of the glass between the waters' surface and the light. The light in my 15T looks very uniform...I dont see any shadows or areas with no light exposure. This was true even with the 10 Watt bulbs. I have a single 10Watt PC over a 5 gallon tank as well. This bulb sits on the far left side of the fixture, so when it is on, you can tell that the light is not quite uniform throughout the tank, but it doesnt look terribly bad. If I were going to use these bulbs over anything larger than my 15T I would probably elect to build a custom hood with about 4 lamp sockets spaced to evenly distribute light. For this amount of trouble though, you might just find the longer flourescent fixtures and use those. The problem I found when looking at cheapo under-cabinet flourescents is, they dont reflect light straight down..The bulb in those fixtures is usually close to one side of the housing, so a lot of light is emitted through the side of the fixture, which makes perfect sense; the thing is designed to work under a cabinet!

I found the bulbs in the lighting section at Walmart....you can also get them at most of the bigger stores that sell lighting. These are sold for roughly the same price as the smaller 10 Watt PC screw-ins sold in the pet section at Walmart, but the physical size is larger. They are about twice as fat, so take a look at your light fixture and be sure they will fit. Mine were snug and wouldn't fit if they were any larger.

 

[youronlysin]

Also, I dont have any problems with the glass top blocking any light. I keep mine clean, and whenever I do any maintenance that requires me to lift the fixture off the to of the tank, I always clean it...both sides. Water does condense on the bottom (tank) side of the glass, but the side near the lights stays perfectly dry. If you start to get any white crust on the glass, try to get ahead of it and soak the glass in vinegar for a few hours and scrub it well. If it gets terribly bad and is left on for too long, it can etch the glass and there isnt a chemical in the world that will remove that. Its easy to keep up with if you just clean it once in a while when you do tank maintenance. In my opinion, your very smart to use glass over the tank. My aquarium bulbs have been over water before but, over time, the bases corrode making them hard to unscrew, the bulbs get crusty growth and those are hard to clean. Not to mention the water evaporated a lot faster. Id pay the money for glass and strip lights. Those will make you happiest in the end. Id you can save up the hundred bucks for a nice 96Watt PC fixture, youll be even happier, but thats an expense that a lot of people have a hard time justifying. Your plants will thank you though.

 

[BASSNMAN]

I went to a local glass shop and had 4 pieces cut to fit my 125 gal. The pieces toward the front of the tank are not as wide as the rear sections. This lets me open to feed and have the lights over a solid piece of glass. Also cheaper than buying them at LFS. I epoxied blocks of plexiglass on as handles.

 

[mattrox]

All tanks built in Australia seem to come with glass lids cut to fit. They have strips of glass siliconed in place as a lip. I will attach a pic to illustrate.

On my tank a brace has been siliconed in the center and a lip created below it so the lids are a manageable size. The handles are siliconed on too. This is quite typical of what is available here.