What Type Of Foam For Under Tank

[RossW]

There was a recent discussion about the proper fitting of foam between tanks and stands.  I am now confident I know what size to cut my foam to, what I am not sure about is what type of foam to buy.

Do I just go to Home Depot and get a standard 1" rigid foam insulation?  Does it have to be 1"?  Can I use a "closed cell foam sleeping pad" instead?

Thanx for the guidance.

BTW, this is for a 48" 75g and 90g tank.

Ross

[babblefish1960]

For the best benefits when setting up your tank, either pink or blue extruded foam is the better choice. One inch is common, but there is a half inch pink for very cheap that is good too.
White foam,the sort that looks like corn kernels stuck together, do not use this, it is unstable in its consistency and you may end up with pockets.

The mattress foam you speak of won't hurt if it is not too thick, it just allows some leeway between small imperfections, but it has no real support, and not much in the way of insulative value either. Moreover, any of these flexible foam types are not well suited to water accidents, they will keep the water, a generally bad idea.

[RossW]

One of my concerns is the appearance of this 1" foam piece, thus the 1/2" pink might be what I want.  Also, the imperfections in most stands are probably less than an 1/8" of an inch max. thus a 1" buffer seems like overkill.

The reason I like the mattress foam is because it is relatively thin and not as obvious to the eye.

[RossW]

Moreover, any of these flexible foam types are not well suited to water accidents, they will keep the water, a generally bad idea.

This makes me wonder if I should not put a towel between the tank and foam, and between the foam and stand.  My thinking on this is it will provide a better chance for things to dry out after an accident even if it is extruded foam.  Or, will the water eventually evaporate w/ the extruded foam.

[DavidJohnson]

This makes me wonder if I should not put a towel between the tank and foam, and between the foam and stand.  My thinking on this is it will provide a better chance for things to dry out after an accident even if it is extruded foam.  Or, will the water eventually evaporate w/ the extruded foam.

The problem with a towel is that it might wick the water under the tank possibly resulting in mould/mildew issues (or worse, causing a wood stand to rot) and it's not like you can pull the towel out and wash it.  Foam will act more as a water barrier which is good.

[babblefish1960]

Don't use a towel, you would be introducing something that wicks water under the tank and cause problems for the stand down the road. The extruded foam won't actually let water pass underneath, capillary action notwithstanding, the pressure on the foam from that size of tank will exclude any water from entering under the tank.

The half inch pink foam is quite inexpensive, and you can trim it with something that matches either the tank or the stand and not ever think about it again.

[RossW]

OK, no towel, my bad

I am leaning towards the extruded foam... the question is 1/2" or 1".  My gut is telling me 1" is the tried and tested way to go.

When trimming the foam, do you leave any extra or cut it to be completely flush with the outside of the tank?  Part of me wants to leave an extra 1/4" or so.

[babblefish1960]

Either will work fine, if you do cut it flush, don't undercut, make sure it is a perpendicular cut. If you want to leave a 1/4" hanging out the side, by all means, please yourself, it is your tank.

[darkdep]

I use the white foam, 1/2", under all of mine.  1"?  Thats unnecessary.  All you're doing is absorbing irregularities in the stand top.

[Saltcreep]

I've used many of these types of pads and, without doubt, the best product I've found is anti-fatigue matting. It's also sold for use in playrooms and the like. You get sixteen square feet for less than twenty bucks and it comes in colours. It's closed-cell foam about a half inch thick and what I like best about it is its resilience. It doesn't take on permanent depressions like any styrofoam does. Also way cleaner to work with. I realize it's all personal preference but, for the life of me, I can't figure out why more hobbyists aren't using this stuff. You can get it almost anywhere now and I've seen it on sale at a very reasonable price. You can see it on my workshop floor in one of the pics in my gallery.

[audioslave_36]

I used 1" blue Styrofoam SM under mine, only because there is 2200lbs of water plus the tank and everything else. surprisingly enough the foam is still an inch thick with all that weight on it, so half inch will be fine for your two tanks Ross.

[normc]

I have the pink 1in under one tank and and the blue sleeping pad under my tall 50. No problems with the blue stuff but it compressed to about 1/8 in so won't help with some irregularities.

[dan2x38]

As for the weight compressing the foam I thought that right off. I am surprised it is still the same thickness. I thought the 1st day it would have squished some.

[RossW]

I just removed some closed cell foam from a stand I had and it had compressed significantly.  I believe this to be a good thing.  I could see different levels of compressions which I attribute to the foam absorbing the irregularities of the surfaces.

I am starting to think that if the extruded foam is not deforming is it absorbing the irregularities?  I would expect to see dents where the tanks sits.

BTW, not only did I put this foam under the tank but I also had it under the stand.  I have hardwood floors and I believe there are more irregularities with my floor than with the top surface of my stand.

[audioslave_36]

Well I don't doubt that my foam has compressed to some degree, just not as much as expected from 2200lbs of weight sitting on it.