# Comments on DIY 300g stand with lg sump



## chiroken (Sep 25, 2007)

96Lx24Dx31H, 300 gallon african cichlid tank with 72Lx22Dx20H 115 gallon sump. I'm taking this design off of what the previous owner had used, with some modifications. Previous stand showed warping on the outer edges of the plywood inbetween the 2x4 legs as the horizontal 2x6 ran on the inside of the legs. The weight of course is primarily on the outer tank edges. To keep the tank stand narrow as possible, but to have enough room for the sump to fit, the 2x4's need to go on the outside of the 2x6. The end product will be a hardwood finished stand, hood and matching end cabinets with shelving above.

This is what I've come up with so far as the first phase, creating the initial shell of the stand. 2x6 horizontally running inside of the 2x4 legs. 2x2's running at the base of the legs to create sump platform, also on inside of legs. Stand depth is 25", leaving 22 1/4" inside legs to fit 22" wide sump tank. I could run 2x4 cross braces front to back between the 2x6's if I want, the current stand didn't (reef tank with 750lbs of live rock in main tank). Top of stand and lower 2x2 deck to be covered in plywood (3/4" probably)
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They I am planning on adding a 2nd 2x6 glued and screwed between each leg front and back. This should prevent the ply from warping due to tank weight. Add a 2nd 2x2 between the legs at the bottom as well (front only). This functions (along with the 2nd 2x6's) to create a flush surface that I can then face with hardwood and fasten doors to etc. Just a single 2x6 and 2x2 on the ends are needed to make it flush. You can see in the next diagram where I've shaded in the 2nd set of 2x6's.
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The plan is to then build matching cabinets with shelving units above on either end of the tank. The cabinets probably 18" deep with the shelving units probably 12" deep. Should give nice change of depth. These would be 30-36" wide on either side giving a total width of 13-14'. The end units will run floor to ceiling and need to be removable to be able to remove the sump. Then finished end panels of the tank stand will also need to be removable for the same reason.
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I have yet to figure out the canopy. Thinking of having it go from tank right to ceiling, lower section to house lights, upper section to be open "box" cubbies. Any concerns/challenges/improvements you see with this design?


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## lilscoots (Mar 13, 2012)

Most people (myself included) would recommend having the top rail sit on top of the vertical legs not "hang" from them with screws/bolts. It would save you from having to glue and screw additional 2x6's between the legs. I feel better with the weight being supported directly by wood instead of depending on screws/bolts, especially for that mass of water. 
Here's a pic of the frame for my 125. (the weight is supported directly by the vertical 2x4's)

As far as the canopy goes, having it go to the ceiling with cubbies above may be problematic if you ever need to do major cleaning/maintenance/rock removal. Most canopies allow you to lift/tilt the entire top up for that purpose if need be, with the cubbies above it seems like that wouldn't be possible.

The surround looks great. I like the idea of making it look integral.


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## chiroken (Sep 25, 2007)

I do have the weight directly supported by vertical wood, I have 8 vertical 2x4 posts that carry load directly from the tank to the floor. Best kind of support as far as I know. You are correct in that some weight will be carried by the laminated 2x6's but I think most weight will be on the 8 2x4's. I am not an engineer though. I've seen your type of stand before and it obviously is structurally strong enough. I always have concern when vertical load bearing points aren't carried through to the floor. I see your weak points being at the top and bottom of the 6 vertical 2x4's (3 each side) where they would not withstand as much shear force. They are "balancing" so to speak on screws driven into the horizontal pieces. <edit: I should add the shear forces would be worse with the middle 2x4's as your side end 2x4's have the end 2x4's for stability, glued and screwed or however you attached them. end edit> Again, tanks aren't crashing so it is clearly working. I wonder what would happen if there was a slight tremor and the tank swayed abit?

Your 4 end 2x4's carry load directly to the floor which I really like. I don't have that luxury with that type of construction as I need to keep the ends open in the event I need to slide out the 6 foot sump.

I hear you about the cubbies. I was thinking I'd have to have the light portion at least 12" high or higher to allow enough room to get into the tank. Speaking of getting into the tank. I need more than 12" in get into it. It was previously a reef tank with coraline algae on the glass. I literally climbed into the tank with my bottle of vinegar and my stainless steel glass scraper....what a job 



lilscoots said:


> Most people (myself included) would recommend having the top rail sit on top of the vertical legs not "hang" from them with screws/bolts. It would save you from having to glue and screw additional 2x6's between the legs. I feel better with the weight being supported directly by wood instead of depending on screws/bolts, especially for that mass of water.
> Here's a pic of the frame for my 125. (the weight is supported directly by the vertical 2x4's)
> 
> As far as the canopy goes, having it go to the ceiling with cubbies above may be problematic if you ever need to do major cleaning/maintenance/rock removal. Most canopies allow you to lift/tilt the entire top up for that purpose if need be, with the cubbies above it seems like that wouldn't be possible.
> ...


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## lilscoots (Mar 13, 2012)

chiroken said:


> I do have the weight directly supported by vertical wood, I have 8 vertical 2x4 posts that carry load directly from the tank to the floor. Best kind of support as far as I know. You are correct in that some weight will be carried by the laminated 2x6's but I think most weight will be on the 8 2x4's.
> 
> I wonder what would happen if there was a slight tremor and the tank swayed abit?
> 
> Your 4 end 2x4's carry load directly to the floor which I really like. I don't have that luxury with that type of construction as I need to keep the ends open in the event I need to slide out the 6 foot sump.


Sorry, it looked like the tank perimeter would have been sitting on the 2x6 inside the verticals, I prefer a flat perimeter beneath the tank to avoid stress points where one vertical might be longer/shorter than the others.

The original stand for my 180 was built like your design and I can assure you there was far more sway in that design than in my design, the L'd 2x4's in the corner remove any sway (I can slide my 125 3/4 full on a rug on hardwood floors in any direction with zero wobble, I've had to do this quite a few times as we're remodeling the room it's in). Unfortunately in your case, because of the sump width you won't be able to do that.

As long as the perimeter of the tank is being supported directly by wood and not screws, your stand should hold vertically, I worry more about horizontal wobble, but maybe that's what the extra 2x6's between the legs are there to prevent? If so, the tighter they fit between them, the better, leave no "wiggle room" as it were.


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## chiroken (Sep 25, 2007)

I see what you say about horizontal wiggle and the legs needing to be dead on. The additional 2x6's would need to be a tight fit for sure and I will be glueing everything so I don't think wobble will be an issue. If there were any minute differences in that horizontal surface I am assuming the 3/4 ply will have a tiny bit of give but I also plan on putting 1/2" pink stryofoam on top of the ply, under the tank (the prev owner did this too). Even if the flat surface was 2x6's show me 4 pieces of lumber that are all 100% dead true/straight! I can L the corners like yours but then the overall width front to back of the stand needs to be 4" larger meaning the stand will stick out that much more from the wall which wouldn't be favourable.


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