[FischAutoTechGarten]

Folks,

I have a mini-rack of 20gallon long aquariums. Each aquarium is illumated by 2 x 12.5" 6W 8000kk Stunner Strips with the reflectors. It's fantastic.

However, I don't yet have lids for my aquariums as they 20 gallon longs that are rimless/baseless (DIY) and I really enjoyed the look. However, I'm finding maintaining 27degC (80degF) to be a challenge, despite 25W heating cable in each of the 4 20gallon display tanks... and supplemental 200W in the dual chamber sump. That is 300W of heat in about 95-100 gallon total. Too much. My evaporation is also quite significant (5+ gallons a day... dry desert..even if it is winter).

Last night, I placed thin styfoam on each of the 20L aquariums and the 20L sumps (it's a dual chamber sump.. quite large). I noticed that the 200W heater went out within 2 minutes.... so I unplugged it.... I maintained 27.5" all night long (I graphed the RTD measurements) with just the 25W heating cables in the four aquariums (so 100W total), with nothing supplemental being added in the Sump. Huge difference. Convinced me that I need to get lids.

I can go with something completely flat on the display tanks, as I only need a tiny cut in the corner to allow for the heating cable leads to escape the tank. Chamber 1 Sump can use a completely flat piece that is 25" long as I have a raised portion on that part of the sump for the filter bags... The Chamber 2 Sump will need several corners cut as there is an auto top-off waterline, supplemental heating cord , 5 probes and 5 level switches.

Where I struggle is material. I don't want to diminish the effectiveness of the LED Strips. They sit about 10" above the open water surface presently... and the light is very nice. I know anything will block/reflect .... lexan, glass, plexi-glass, acrylic, etc... I'm leaning towards glass for clarity, but it's heavy and they can break easily. I worry about the other materials blocking too much light or become hazy with time.

I could use some suggestions and anecdotal evidence...

Here's the mini-rack... (called the Sonoran Desert Fish Nook).

Typical Top of Aquariums.

 

[jeffkrol]

Well first since you have little ( no) uv any plastic/glass is fine.

Double wall polycarbonate is the less breakable option.
Cell cast acrylic is tied w glass for the clearest as to light transmission.

Regular acrylic warps due to moisture absorption.
Lexan has a mixed track record for warping though seems minimal. The double walled don't have this issue apparently.
May be a thickness thing.

Double walled may lose about 20%
Glass/sheet plastics about 10-15% rough estimates

Framing and aesthetics will prob the difficult part

 

[zitasowell]

I did everything, thanks for help.

 

[FischAutoTechGarten]

I ended up going with glass. the only issue with glass (well beyond it being fragile and the need to treat it with kid gloves), is they way it cools and holds moisture relative to the surface. I get water droplets clinging to it. I'm using 95% RO Water, so I'm not getting any resulting calcium spotting, which is good.