Stand question for the DIYers

kwl1763 · 02-12-2006, 03:29 PM

Ok question for you DIYers.

Unfortunatly my contractor started on my stand for my 450 (120"x36"x25") before talking to me which I specifically told him to get with me before.

So here is what I have so far. It's all 2x6

What should I tell him about beefing up the corners, additional center bracing, etc.

mojo · 02-12-2006, 05:41 PM

Is it an acrylic or glass tank? There will be a big difference in stand construction depending on the type of tank.

Do keep in mind that a 4' 2x4 can withstand about 4,000 lbs of vertical force before failure. With a 450g tank of saltwater, you're still under that with each post, although you'll obviously want to design in weight distribution to account for pieces of wood that aren't perfect, etc.

bauerbach · 02-12-2006, 10:09 PM

the precision of the stand is far more important than the wood used. as mojo said, wood is way stronger than we give it credit for.

but wood is horribly imperfect as far as being straight. and thats a problem for a fish tank. bottom line the surface the tank is on needs to be flat, smooth, and level. aside from that nothing else matters.

RobinsonFam1 · 02-12-2006, 10:44 PM

on the structural side it is more than enough. if you are going to put equipment under it now is the time to plan for access. if you need to put beams in let me know...i have an LVL laying in my garage you can HAVE...please take it actually! LOL

once all that is complete i would add a product called Advantech. it is an OSB subfloor with great moisture resistance properties. you can also seal it as well too.

as a builder and tank stand guy i can swing by your place and make sure youre ok if you need me to. im not that far from you either.

Brandon

kwl1763 · 02-13-2006, 10:07 AM

Thanks Brandon I may PM you a little later. I have instructed him this morning to shore up the corners and add a couple cross braces if nothing else then to screw in the plywood. I stressed the importance of having the thing perfectly exactly laser level since I know this will be most important. I'm going to cover the whole room including this thing in KILZ sealent then bildge paint so it's totally waterproof.

I really don't need access to the underside. the sumps are remote. I am going to build a shelf up high for the ballasts so just a couple pumps under there. Maybe some dry goods storage, etc.

mojo · 02-13-2006, 10:12 AM

Again, your tank type will make a difference on the construction. Glass only needs to be level around the edges, and no center support should be used. The weight will only be around the edges.

Acrylic should as level as possible over the top of the stand, then use a foam pad to smooth out any imperfections. The weight will be distributed over the top, so you'll need bracing in the center of the tank as well.

kwl1763 · 02-13-2006, 10:17 AM

Sorry Chris. Ya it's glass. That's why I'm not to worried about the center support.

Blorton · 02-13-2006, 11:28 AM

I would add diagonal braces longways on each side to help keep things from "racking". I would also add braces across the top between the long sides to keep that portion from spreading apart like a clam. that would be bad, emmkay?

Personally, I would use at least two thick layers of mdf as a base for the tank. Even though it's not acrylic, it certainly wouldn't hurt to build the base that way, and will make things much easier on moving day.

Cheers!
Dan

mojo · 02-13-2006, 11:33 AM

I agree on using some kind of plywood as a base, but I question MDF, as it expands a LOT when exposed to water - enough that it may stress the tank. I'm not 100% sure if it'd be enough to do damage to the tank, but something to keep in mind. I'd just use 3/4" pine plywood.

MattTVI · 02-13-2006, 11:36 AM

the Pine Ply is a good idea, just make sure it's at least paint-grade or A/C ply so that you have one nice, smooth side... :-)

GeorgeW · 02-13-2006, 12:52 PM

Actually, the room in the picture is an excellent example of what you should do for your stand. The load bearing walls of your basement (should) have a strapping running along the center of the wood (paralell to the floor) to prevent buckling. If you don't need to access the bottom and really want to over-engineer it, you will increase 4x (approximately) the support capabilities by either using metal strapping (just like the kind used in your basement) or sections of wood nailed between each set of uprights, midway between the floor and the top. This causes the points of stress to be 1/2 the distance as before, but require two failures (top and bottom) to buckle.

mojo · 02-13-2006, 01:09 PM

Also- I'd recommend having seveal packs of wood shims on hand when you plan on adding water. The wood will warp and bend in some places more than others. Obviously, you can use the water in the tank as your level.

GeorgeW · 02-13-2006, 03:41 PM

On a semi-related note: pressure treated lumber is generally straighter/truer than stud. Anyone have any definite opinions for or against using pressure treated wood? I know it's treated with arsenic, but it's not like it's dripping into the tank.

Schwaggs · 02-13-2006, 03:55 PM

Pressure treated may be truer when first purchase but as it dries, it usually warps.

On a tank that long, I would use LVL as the contact point between the stand and tank. LVL beams are perfectly true and will stay that way...

RobinsonFam1 · 02-13-2006, 10:59 PM

stay away from pressure treat. i can almost gaurantee it will warp. stay away from MDF and particle board too.

PT wood is no longer arsenic as of 1-1-2004. Govt siad it was too dangerous due to playground equipment and whatever else....so now they make it with some copper base product...this product will eat a standard steel nail in 2 mos they say....yeah..thats safer!