Acrylic Aquarium Cover

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

itafx

Aquarium Advice Freak
Joined
Feb 19, 2007
Messages
405
Location
Virginia
I went to Lowes and bought some .22" acrylic and made an aquarium cover. I was greatly disappointed that it warped. Does anyone know a better material for this?
 
it would be helpful if you put your tank information into your profile. we dont know if you are trying to cover a 10 gallon or a 125 gallon tank.

.22" acrylic is not really designed to span large horizontal distances. it will bow under its own weight. a better material would be thicker.

~mike
 
Thanks. I should do that when I get a little more time. I didn't even realize there was such a thing as posting tank information in my profile. In the mean time, the answer to your question is that I made covers for 10 gallon and 29 gallon tanks and they both bowed miserably. They are almost a quarter of an inch thick and that stuff isn't cheap. There must be a better material or acrylic tanks wouldn't hold their shape. I just don't know where to get it.
 
Acrylic, in general, isn't really a top choice for making a top. Glass is typically the preferred choice. In fact, I don't think I've ever personally seen an acrylic tank top in any size. Hmmm.
 
I've purchased several Marineland hoods that include a combination of opaque and clear plastic materials of some kind and they hold their shape just fine. I was looking for a cheaper and more versatile DIY solution, though.

Glass is hard to cut properly, easy to cut yourself on the sharp edges, and easy to break unintentionally.
 
Are you trying to seal the top of the tank because of jumping fish or just because you want to? Either way have a look at eggcrate...the material used in floresent light fixtures in office buildings.....also seen in tanks at LFS to hold coral frags ect...it's much cheaper then 1/4 acrylic and will not sag like the acrylic will also it will allow the O2 exchange needed....HTH
 
itafx said:
I've purchased several Marineland hoods that include a combination of opaque and clear plastic materials of some kind and they hold their shape just fine. I was looking for a cheaper and more versatile DIY solution, though.

Glass is hard to cut properly, easy to cut yourself on the sharp edges, and easy to break unintentionally.

I wonder what that material would be. You could look for cell-cast acrylic, but that's significantly more than the typical extruded acrylic.

Go and look at Lexan. It's like acrylic, but is thicker and stronger, in my experience. I think it will work for you. It's just a tad more expensive than acrylic at Lowes/HomeDepot. And keep in mind the typical "acrylic" is either Plexiglass, Lucite, or Perspex, so when looking for a different option, look for something other than those.
 
Ziggy953 said:
Are you trying to seal the top of the tank because of jumping fish or just because you want to? Either way have a look at eggcrate...the material used in floresent light fixtures in office buildings.....also seen in tanks at LFS to hold coral frags ect...it's much cheaper then 1/4 acrylic and will not sag like the acrylic will also it will allow the O2 exchange needed....HTH

Objectives:
1. Keep fish from jumping out
2. Support floresent and LED light fixtures
3. Limit evaporation (extremely dry in winter. Accelerates evaporation)
4. Leave adequate holes for filter and heaters. (Not easy to shape glass)
5. Have a hinged lid portion I can lift for feeding and management (not impossible with glass, but not that easy either. I have one aquarium with a hinged glass top, but I got it from a DIY previous owner and the glass didn't get cut perfectly and doesn't fit the tank that well.
 
I'm guessing then that this is a FW tank? I have a 55g FW with evap problems too. Actually all of my tanks evap like crazy because we use a wood stove to heat our house. My Reef tank has an auto-top-off system on it and the FW tanks I just add water to them as needed.

I'm still not sure how you have everything set up but if you are putting you lights right on top of the acrylic then that will cause it to bow...the heat and the weight from the lighting even if it is NO low light those bulbs still get hot.
 
Yes, it's FW. Wood stove heat is driving our evap up too. I have a thin layer of plastic and air gap between bulbs and the acrylic. I just went out and felt the acrylic. It was warm to the touch, but not hot.

Your tanks look really nice. I did SW when I was younger, but I'm not ready for the cost and care requirements right now.
 
Could you build a wooden hood and mount the ligts to it? That would keep it up off of the acrylic and looks nice. I have an acrylic tank and am having the same problem. It actually came with acrylic covers for the lights and they do warp. I stuck two little pieces of wood on each end of my light to hold it up a few inches...just like two little risers. It helps just to give it more airspace. But It could use more.


I saw this link earlier today in another post and shows you what I think will work best for a cover on my tank.
http://www.melevsreef.com/29g.html
 
Glass is far and away the best material for covers. The sharp edges are easily dealt with, by dragging a bottle or spare piece of glass back and forth along the edges. An alternative to folding tops are sliding ones, using E channel, which is used for sliding doors on DIY projects, and is available at building stores.
 
I work in the sign industry and I cut lexan, bi-carbonate, plexi and acrylic all day long, and none of them will hold their shape on top of a tank unless you used a minimum of 1 inch thick, so do yourself a favor and get an 1/8 inch glass top from a glass shop and get plastic hinges. I once tried half inch acrylic and it bowed the first day. The plastics that marineland uses is not plexiglass, it is more of a clear ABS or pvc. But even then, they are just used in small sections for light bulb windows on black ABS plastic hoods, not entire tank top spans. For that they sell kits made from glass with the plastic hinges as I described.
 
Sicklid said:
I work in the sign industry and I cut lexan, bi-carbonate, plexi and acrylic all day long, and none of them will hold their shape on top of a tank unless you used a minimum of 1 inch thick, so do yourself a favor and get an 1/8 inch glass top from a glass shop and get plastic hinges. I once tried half inch acrylic and it bowed the first day. The plastics that marineland uses is not plexiglass, it is more of a clear ABS or pvc. But even then, they are just used in small sections for light bulb windows on black ABS plastic hoods, not entire tank top spans. For that they sell kits made from glass with the plastic hinges as I described.

What you say makes sense, but then what do the acrylic aquarium manufacturers use for their tanks so it doesn't warp? I have a Clarity Plus 72 Gal Bowfront and it holds its shape beautifully. The thickest part is the top cover and it's only 3/8".
 
What you say makes sense, but then what do the acrylic aquarium manufacturers use for their tanks so it doesn't warp?

This relies on the fact that all sides, top, and bottom are welded to each other (or possibly cast) together for structural rigidity. If you take a flat piece of acrylic and just lay it on a rim with nothing to hold up the center, it doesn't take much heat (aquarium lamps are more than enough) to soften it and make it curl...
 
One of my big problems with glass is I don't have any way to cut it on a curve. I'm trying to cover a 46 bow so my SW tank doesn't evaporate 10% per day in this dry winter weather. I've personally verified on a 20 gal that 1/4" cell cast acrylic warps, something the guys above in the thread already implied, but I found it out first hand. My next try is 3/8 inch cell cast with perpendicular strips bonded onto the most warp-prone parts for stiffening. I also found a source for acrylic hinges which would be a nice touch if they work.
 
I use 1/4" Plexiglas/Acrylic sheet from Home Depot or Lowes. After years of cutting this stuff with a Bosch jig saw, or the old razor blade method my success rate was about 75%.

A month ago I started to cut this with my table saw. I am totally amazed how easy it is with the table saw. I can now cut perfect lines and circles by using the table saw. I am using a carbide trim blade and although one would think this would fuse the Plexiglas back together, it does not.

Try the table saw method, you will like the outcome!

http://www.aquariumadvice.com/gallery/showimage.php?i=12184&c=searchresults&searchid=19
 
A note on the tank information area of the profiles: Not everything has been imported from the old site yet. I know the admins still have lists of things to do and getting the tank info over is on the list. They are working very hard and I'm sure it will be available soon.
 
I've been using a saw table all along and agree, it works great, except when you have to do cut outs or curves. Then it gets a little harder. I tried 1/4 inch plexiglass from HD and found it warped horribly even on a 10 gallon tank. Next I tried 1/4 inch cell cast from Delvies Plastics and it warped too. This weekend was my next DIY try at an aquarium cover. I used 3/8" cell cast and put a double thickness strip along the most vulnerable (to warping) section. I used acrylic hinges. I've had the thing on a 20 gallon for 26 hours - no significant warping. It looks like that's going to be the ticket. it's wonderful. No black strip hinge to block the light. No excessive evaporation like all my other tanks. I took measurements on my 17 tanks to get ready to go into production. I plan to make a big buy to save on per unit shipping costs and get quantity discounts on the plastic. If anyone knows a better source for cell cast acrylic, I would definitely be interested.
 
Back
Top Bottom