35 gallon hexagon fish tank lid

HELP please I Bought a used hexagon tank quite sometime ago, and was told it was either a 29 or 39 gallon tank. I’ve measured it and use the online calculators to try to find out how many gallons it is, but I keep getting different answers for every site I try. The last one said it was a 39 gallon or actually, 38.785 or something like that. Can someone help me with that figure please? One panel measures 11 3/4 inches wide and 24 inches tall. That comes to around 35 or 38 gallons. Can someone confirm that for me please? The next problem and this is the big one, I cannot find a hexagon size tank cover anywhere for more than 10 gallons. Does anyone know where I can get a Hexagon cover for my tank? Thanks for your help

I’ve attached pictures to show you the type of tank it is. Doesn’t look like a hexagon in this picture but it is. 6 sides.

Your units are in inches, so your answer will be in inches. so it is 8608.73 cubic inches. That is then converted inches to US gallons or whatever unit you want. That answer is 37.27. so approx 37 & 1/4. gallons. Mine is 59.54 gallons. The cover I have is handmade. what do you mean by a cover, a glass lid? You may be able to get a glass company to cut you a lid and sand (smooth) down the sides. You can have it cut it in 2 and use hinges made for glass from a place like "glass cages."

Thank you Kalyke. I’ll go with 37 1/4 gallon. Yes I mean a glass or plastic lid. It came
with s broken plastic lid. I’m sure there’s an aquatic word for the lid or cover but I can’t think of one. Seems no one sells these so I guess I will need to go custom. I’ll check with a glass company. Thanks so much for your suggestion.

Your units are in inches, so your answer will be in inches. so it is 8608.73 cubic inches. That is then converted inches to US gallons or whatever unit you want. That answer is 37.27. so approx 37 & 1/4. gallons. Mine is 59.54 gallons. The cover I have is handmade. what do you mean by a cover, a glass lid? You may be able to get a glass company to cut you a lid and sand (smooth) down the sides. You can have it cut it in 2 and use hinges made for glass from a place like "glass cages."

Aha!! Hood!! I think it’s called hood.

Hood.

I literally just got done cutting a polystyrene lighting panel from home Depot into a lid for my 29g. They come in long sheets and won't break the bank. It is also clear so my light shines through perfectly. Pretty easy DIY project, took me 15 minutes

I just remeasured my tank with a cloth measuring tape instead of metal. It is exactly 11 1/2” by 24”. That comes to 35.677 according to the conversion chart. The 35 gallon hoods I’ve seen so far don’t measure the same. So I think DIY is the only way to go. Thanks for the help.

Hi, thanks. Since I tend to keep my water level a bit lower anyway, my 59.1/2 an inch is probably really more like 57. I think the math is hard too. I did not grow up with the kind of math kids can do today but it is something like " figure out the square inches of the hexagonal, and then multiply that all by the height of the tank, then convert inches (cubed) to gallons.
I'd get some cardboard or poster board, and outline your tank in sharpie. Bring that pattern to a glass or acrylic cutter, (you can also cut it yourself). If you want it to hinge and open, then draw that in too. You do not want to accidentally make it and realize it is too small. If your fish tank has a frame with a lip, you can decide if you want it in or out of the lip. Remember also that the fish actually need air, so that needs to be accounted for.