What type of acrylic to use for cover glass?

[Anonymous]

Been thinking of adding a cover glass to my tank mostly to prevent problems down the road with jumpers. Since I've got a custom tank I can't just buy something off the shelf, but I had the bright idea this morning of maybe using the acrylic they use in frames these days.

Companies like www.americanframe.com will custom cut acrylic sheets to very exact specifications and getting what you'd need for a tank top will literally only cost a couple bucks. But they offer three different types of acrylic and I'm not sure which is best suited for this purpose.... Standard ACRYLITE FF-3, UV-filtering ACRYLITE OP-3 or Non-Glare ACRYLITE FF P-99.

Anyone have any input over which of these might be the best choice? I'd like whichever will block the least amount of light.

 

[Anonymous]

I would not cover the tank. Better gas exchange and better evaporative cooling.

Maybe you can use a egg crate light difuser?

 

[Anonymous]

Gas exchange isn't really an issue. The tank features a full back length overflow (20") into the rear sump, and that will remain uncovered.

Eggcrate's not really an option both for aesthetics and because when you're using a single halide eggcrate seriously cuts down on light output along the edges of the tank.

 

[Anonymous]

>...cost a couple bucks

What is the dimension of your tank?

How close it the top of the tank to your light?

I would go with the regular acrylic, but if it is too close to the lamp, it may wraps and became brittle over time.

 

[Anonymous]

Wont the tank build up allot of heat with a MH over the tank? I believe you dont have a chiller from a previous thread.

 

[Anonymous]

What is the dimension of your tank?

Overall 20" x 24", but I'd only be covering the tank proper portion of it so I'd need a piece around 19"x19" or so.

How close it the top of the tank to your light?

About three or four inches to the bulbs.

I would go with the regular acrylic, but if it is too close to the lamp, it may wraps and became brittle over time.

Ah well, that part's not a big deal - cost for one of these is only around $7, so having to replace it one a year or so is no problem.

 

[Anonymous]

Maybe make a screen out of the plastic gardening screen material. Its sort of rigid.

 

[Anonymous]

Wont the tank build up allot of heat with a MH over the tank? I believe you dont have a chiller from a previous thread.

Nah. Lights are vented properly, run with good fans. It's just 1 150w halide and 2 65w PCs, so not a huge amount of heat there to begin with. Even if a cover raises temps by a couple of degrees (and honestly, I don't expect it to have that much effect) it won't be a problem. Only thing that was making my tank run hot was the mag drive pump I was initially using as a return, and that's been replaced.

 

[Anonymous]

Maybe make a screen out of the plastic gardening screen material. Its sort of rigid.

I've thought it, or even using nylon fishing line woven like a tennis raquet grid and attached to a frame. Tricky to do either though and accomodate the legs my light fixture stands on, so I lean towards trying the simple & cheap acrylic sheet as a first go. If it gives me problems I can always try to work out one of the other options, and I'd only be out $7 so no loss there.

 

[Anonymous]

cj,
Have you considered something like this?

 

[Anonymous]

Wouldn't work with my light fixture, Matt. See....

 

[Anonymous]

I tried using a sheet of 1/8th acrylic (I think - it might have been 3/16") over a freshie planted tank with a PC lamp 4 or 5 inches above it - the acrylic sagged pretty badly. If you do this, go with a much thicker piece of acrylic than you think you need (at least .25" - and even that might not do it).

jayo

 

[Anonymous]

Hrm. Okay, that pretty much nixes using the source I had in mind. The frame shops only use 1/8th and 3/32nd thick acrylic. Guess I'll have to order a thicker piece from someone like JMK Displays then.

 

[Anonymous]

Mine got browned within two days, and it is 3/16 inch. Maybe it is too close to the lamp, but I continue to use it even after it is all bubbly and crazed.

Can't you go with regular window glass?

 

[Anonymous]

Can't you go with regular window glass?

Sure. I'd just prefer not to

Figure now that I'll just wait til I'm back from vacation, then get a couple acrylic sheets cut to size and piano hinges from http://www.jmkdisplays.com/sheet.html

Think 3/8ths is thich enough, or should I run right up to 1/2"? Hell, come to think of it if I have to end up with 1/2" I'll just have him build me a frame out of it and use it for the fishing-line-tennis-racquet-grid idea.

 

[bleedingthought]

Can't you go with regular window glass?

Sure. I'd just prefer not to

Figure now that I'll just wait til I'm back from vacation, then get a couple acrylic sheets cut to size and piano hinges from http://www.jmkdisplays.com/sheet.html

Think 3/8ths is thich enough, or should I run right up to 1/2"? Hell, come to think of it if I have to end up with 1/2" I'll just have him build me a frame out of it and use it for the fishing-line-tennis-racquet-grid idea.

Lowes has 1/4" and I think they might have 3/8". Check homedepot also.