Building 90g tank stand

[Malvos]

Just looking for some tips on building a tank stand, something simple and strong for my 90g tank.  Three plans I like are:

This one has a simple design and I like the idea of having a top plate like in this one.  Is the styrofoam top necessary (see second plan) to distribute load?  I was thinking of doing a Cichlid tank and if I put heavy rocks in there will likely be points along the bottom that could use the extra support.  Finally I would probably put a trim around the top like the one seen here.

Just looking for some insights or seeing if someone has more detailed plans they'd like to share.

[Saltcreep]

Either of the plans will work fine, although #2 is way, way overbuilt. I wouldn't bother with mitre joints in 2 X 4 lumber either. Butt joints are fine, just glue 'em and screw 'em. The key to any stand is to make sure the load is bearing on the compression strength of the legs, not the shear strength of nails or screws.

[JetJumper]

Styrofoam is a MUST!  well, not really.. but for the cost factor.. just do it
So far I have had 1 tank crack on me for not having styrofoam and a VERY SMALL pressure point.  The tank sat for a few weeks with freshwater full.  I added the salt/sand to the water and cracked from this tiny pressure point in the wood.

[Malvos]

Thanks, I'll probably try to do a design based on the ones listed above.  The tank came with a Fluval 303 that I'll put in the bottom along with a built-in power bar and air pump, is there anything else that will need to be accounted for?  I'll probably leave a gap a the top-rear for filter/air hoses to pass through.

[veron]

sorry but styrofoam is not a must or even worth it for any tanks with the plastic trim which is most store bought tanks. The tank sits only on the trim edge so styrofoam does nothing. Acrylic tanks are a different story. Your stand needs to be solid and level thats it.

[dan2x38]

The syro services a great purpose. As the size of a tank increases the pressure created increases obviously. Water weighs 8.5 lbs/gallon. As the size increases and the depth of the tank there is more and more pressure on the glass especially at the lower level of the tank. The foam doesn't level a tank by any means though. The foam serves to relief stress risers. These are created sort of like a fulcrum. No surface is perfectly flat there are humps and bumps over the entire surface we cannot see. When one of these tiny humps/bumps contacts the bottom of the aquarium it creates pressure straight up through the glass pane with an uneven pressure at that contact point. Over time this stress point weakens the glass and eventually can cause failure of the pane and/or joints. For the cost - next to nothing it is well worth the security. It also helps insulate to reduce heat loss (a little bit). This is great for planted tanks since plants love warm feet... Somewhere I read or was told this is more important as the tank size increases over the 30 gallons and smaller tanks not as big a deal but still does the same thing just less risk of failure.

[Malvos]

I agree, but I think veron's point was that with the plastic rim at the bottom makes sure the glass isn't touching the cabinet top.  My worry about adding styrofoam is that I might be transferring the load from the edges (where it was designed to be from the rim) to the bottom of the tank...although now that I think of it if the load is transferred to the bottom pane the only real vertical load on the tank edge would be the upright panes which is nothing compared to the water.

I guess my real point is that do I just put a piece under the whole tank and let it settle or try to trim it to fit under the tank inside the bottom rim.

[veron]

Not to argue but foam gets crushed to a state of complete hardness from the rims edge.
It serves 0 purpose and in fact if the foam is thick enough it could cause pressure on the glass if the trim edges crush it enough. Having owned many tanks and built a few,
not one company recommends foam under there tanks/on there stands because its not needed. If you build a stand out of ply properly and even if theres a tad off the weight of the tank will compress the ply. Only flat bottom tanks with no trim and acrylic are foam recommended and even then thats a stretch.

[JetJumper]

Only flat bottom tanks with no trim and acrylic are foam recommended and even then thats a stretch.

I don't think thats a stretch at all.  ALWAYS use Styrofoam under these types of tanks... ALWAYS!

[Malvos]

So here's what I've come up with playing around in Google's SketchUp for an hour or so:

First pass, didn't like how the horizontal edges at the top had no support.


So I added an extra 2x4 on the corners, but as mentioned before that's probably overkill


Instead I shortened the long horizontal supports:


I will be covering the sides and back with probably 1/2" plywood and putting doors on the front, but wanted to get opinions on the basic frame first.  Top measures 48 1/2" x 18 1/2".

[JetJumper]

I like your option 2 best.


It gives more support for a front to back horizontal aspect so that your supports don't just give out.
Personally I wouldn't have the center supports.  I have seen 120g tanks with out center supports.  Gives you more access to the sump (If you are having one)

[Malvos]

Here's a revised design with 1/2" plywood sides, I'll have to leave an area at the back open for hoses but the middle supports can hold a shelf on one side (canister filter on the other).

[dan2x38]

Not to argue either but I have had a lot of tanks and everyone over 30 gallons and some under always had foam under them. It is not touching the inside of the trim but on the trim. I've never scene the foam compressed that much and I highly doubt it would compress enough to not release the stress risers.

There are many folks on here with large tanks and more than one I know use foam under the trim. For me it is an insurance policy and why would I not do it to prevent a possible disaster.

I understand the purpose of the floating bottom created with the trim now a days and yes they are more safe but it still doesn't releif potential stress risers created by any surface. And yes flat bottom tanks should always be supported with foam I believe.

[ryancarman.com]

I like your option 2 best.


It gives more support for a front to back horizontal aspect so that your supports don't just give out.
Personally I wouldn't have the center supports.  I have seen 120g tanks with out center supports.  Gives you more access to the sump (If you are having one)

i like option 2 however i would extend the end 2/4 over the front and back verticals to lock stuff together,

are you planning on stain or paint

....if paint is your plan then use mdf it's a much better painted finish and i find its easier to work with, just be sure to paint all exposed material because it does swell if it gets soaked