Non-warping materials for solid lid? Or weights on corners?

[Tired]

I want to put a solid lid over my AIO tank, both to reduce evaporation and so I don't have to worry about tiny fish (pico blennies, Endler's livebearers) jumping through mesh. I'll leave the filter compartments open for oxygen exchange.

Is glass the only suitable material that won't warp over time? I'm looking for something I can buy a custom-sized rectangle of to put on top, and acrylic warps. I know I can just flip the lid over every couple of days to keep it fairly even, but that leaves small gaps that teeny fish can get through, particularly if I forget to flip it for a bit too long.

Alternately, how much weight would it take to keep roughly a 2'x3' rectangle of acrylic from warping upward at the corners? I'm assuming a stack of textbooks on each corner would keep it un-warped, but obviously that's impractical, so is there a practical amount of weight that would also work?

 

[Yates273]

This is what I use and it only causes my Par to drop by 20. No warping either. Here it is on my 40. Also have on my 120

 

[SteveMM62Reef]

I took my Rescue Empty Oceanic, to a local glass shop, along with an Aqueon Back Strip, and Hinge. They made a perfect fitted glass top, right down to the curve, for the Aquarium. It wasn‘t very expensive, at Forty Dollars for the 29 Gallon Tank.

 

[Tired]

This is what I use and it only causes my Par to drop by 20. No warping either. Here it is on my 40. Also have on my 120

I've seen this stuff recommended before, and it's definitely looking like a good option, albeit not a very pretty one. Does it happen to do anything one way or the other for the shimmer? I'm hoping to reduce mine.

I took my Rescue Empty Oceanic, to a local glass shop, along with an Aqueon Back Strip, and Hinge. They made a perfect fitted glass top, right down to the curve, for the Aquarium. It wasn‘t very expensive, at Forty Dollars for the 29 Gallon Tank.

Good to know that's an option, though my tank is full and can't really go anywhere for measurements. I could probably figure something out if I went with this solution. Part of my issue is that I either need a Utah-shaped lid or a two-piece lid, for equipment-related reasons.

 

[Yates273]

I can’t say it does much for my shimmer. I never really had an issue with the shimmer in my tank with the lights I’m running. I guess it may have cut down a little on the “disco ball” effect my Primes had.

 

[All_talk]

I think glass is going to be the best choice, you can make a templet with thinner acrylic (or other). Could your two piece arrangement be hinged on the split line?

As to shimmer, I am always surprised when I hear people want less. To me its part of want makes a reef tank look so good. My Kessils are pretty good, but I still miss the crisp pop of my metal halides.

 

[Tired]

Potentially; I'll have to look at how things shape out. I'm supporting a pico tank directly above the main tank, plumbed in, to use as a mushroom lagoon, and I need a cut-out section so the pico won't trap the lid of the main tank. The easiest way to avoid that seems to be not having lid under the pico.

I see why people like the shimmer, but I personally find it somewhat distracting, at least with how fast it is from all the tiny ripples. A slower effect, like you see in the ocean, would be nice.

 

[acrylics]

You can buy polycarbonate sheet and that will work. It can be machined to shape and is pretty much unbreakable.
Polycarb has enough latent moisture that it doesn't warp acrylic does from moisture absorption.

..if routing it yourself, be careful, it's kinda tacky, but can be cut on a table saw and all that - just like acrylic

HTH,
James

 

[reef_1]

This is what I use and it only causes my Par to drop by 20. No warping either. Here it is on my 40. Also have on my 120

I use the same, but I have a cutout just under the lights where I glued a thin 1.5mm polycarbonate sheet which is clear like glass.

 

[Tired]

You can buy polycarbonate sheet and that will work. It can be machined to shape and is pretty much unbreakable.
Polycarb has enough latent moisture that it doesn't warp acrylic does from moisture absorption.

..if routing it yourself, be careful, it's kinda tacky, but can be cut on a table saw and all that - just like acrylic

HTH,
James

I figured out that I'm probably best served using two separate pieces for the lid, so now I'm looking for a seller who will cut the stuff for me, so I don't have to deal with it.

https://www.tapplastics.com/product/plastics/cut_to_size_plastic/acrylic_sheets_clear/508

Any idea if this is polycarbonate? From what I'm reading, acrylic is one thing, and polycarb/plexiglass is another, but they're calling this stuff "acrylic polycarbonate".

Will a 2'x2', 1/4" thick sheet of polycarb bend if used as a lid with support only at the edges?

 

[acrylics]

Will a 2'x2', 1/4" thick sheet of polycarb bend if used as a lid with support only at the edges?

not likely, not much anyway.
Keep in mind; what causes your acrylic lid to warp is not weight or light, but water absorption. Wet side absorbs water and grows and and becomes convex and dry side evaporates and shrinks, thus becoming concave.
Not the same issue with standard polycarbonate sheet.

And no, it looks to be extruded acrylic at Tap.

HTH,
James

 

[Tired]

Alright, I'll look for another place. Thanks.

I'm more wondering about the material sagging under its own weight over time. I'm putting Endlers' livebearers in this tank, which are tiny, so I need the fewest gaps possible.