Starting a 500 gallon build

  • We are currently upgrading MFK. thanks! -neo
jtalley

jtalley

Candiru
MFK Member
Apr 18, 2009
454
0
46
Kansas City
Getting ready to start a 500 gallon project. I will be picking up the tank in a couple of weeks, but it is a 81.5" L x 30" D x 48" H. I am getting the tank only, so I am trying to figure out the quickest way to build a stand for now, since I want to make this a built in when I own a home.

I have been looking at cinder blocks, which seems like it will work, but I am trying to find the best arrangement for a 30" deep tank. I have seen that people prefer inward facing C's or a pin wheel looking setup, but always for tanks where the depth is a multiple of 8, due to the 8x8x16 cinder blocks. I've seen 6", but would still like to know if anyone has built a cinder block stand for a 30".

Also, how many columns going across? Move I have seen have 3 in front and back and then a 2x4 and plywood sheet setup. I will do the plywood on top because the tank is acrylic, but am thinking that more than 3 will be necessary in front and back due to the weight which will approach 2.5 tons.

My floor is carpeted concrete pad, so idea is to place sheet of plywood on floor, build up blocks, top with a 2x4 and sheet top, then decide about making a wood wrap that I can slide in place.

Need suggestions!
 
I've been doing more research on building a cinder block stand and ran into a question. For the plywood and 2x4 assembly on top of the blocks I was planning to run 4-5 2x4 the length of the tank, using joist hangers to connect to two end 2x4s. It seems that most stands I have been using the 2x4 laying on the long side as opposed to short side. I know standing it on its short side will be a lot stronger, and joist hangers should also increase load capacity. This is a heavy system, but am I over strengthening the top?

Going to post some sketch up pics later tonight, but planning to build the tank 1 inch wider all around and put some crown molding on the edge. The reason for this was to increase depth from 30 to 32 inches so I can use 2 - 16" concrete blocks. Also planning use 6 blocks on each end, 2 blocks side by side, alternating the pattern to increase stability as well as some concrete patch between some of the blocks going 3 high. In the span using 3 columns, one in front in the middle and two in the back at equidistance. Needed to allow room for the overflow drain. Also wanted to put a little more support in the back because I simply can and also to account for some of the additional rock weight.

I have built structures for 600 gallon water tanks at my work, but using slotted steel beams and am trying to do something cheaper, also for a much smaller span....but I may fall back on what I have experience with if I don't get any comments!

Here is a picture of the tank for your enjoyment!

IMG_2999.JPG
 
look's good so far not sure about stand though not my knowledge of weather it is sufficient enough or not.

mr.reef24
 
Since I'm an engineer I did the calculations for a wood support that would sit on the concrete blocks, and I really became uncomfortable with the wood work when I started looking at loading tables and what I conservatively estimate the weight of the system to be. So instead, I am looking to see what the cost would be to fabricate an all metal stand, but since I assume that will be costly, I have redesigned how I will do the stand in that case.

Instead of using a 2x6 and plywood support on the top with joist hangers, I am planning to do a steel strut channel frame that will sit on top of the concrete blocks. Since the steel is quite a bit stronger, this also works better to allow longer spans than before (i.e. more storage space).

Unfortunately I do not yet know the drain hole location from the back edge of the tank, so I may have to redesign the top frame slightly, but no spans would increase and the structure modification is an easy fix. Plus I have access to a chop saw and grinder to do all the prep work and then just assemble at my home.

I plan to do 3 of the "double-channel" strut beams running the length of the tank. One in the front, back and near the middle of the tank depth. The middle beam will be slightly shifted forward such that I can brace the front 2 beams with a single block, and the back will have 2 additional blocks since I cannot add a second block to the middle stack due to the overflow drain. For the 2 inward facing c's, a combination of full length and half length blocks will be used to stagger the blocks to add stability, but I do not currently intend to use any other means of securing the blocks to one another.

Depending on the position of the overflow from the edge of the tank, the back beam may need to be made into 2 smaller ones (leaving a space for the drain), but since I plan to run cross beams between the 3 longer beams anyway this makes the integrity no problem. With this structure, it can easily support upwards of 7,000 lbs and I estimate the weight to be around 5500 lbs, and I am happy with FS>1.25.

In regards to cost, it will be more expensive than doing the stand with plywood and concrete alone, but I estimate the cost of the bottom plywood sheets, concrete blocks, and steel to be about $200. Then probably another $150 or so to wrap, install doors and finish. Below is an updated figure of the concrete base, and I will post the spanning steel structure once I have the overflow information.

Would still appreciate comments!

standbase.jpg
 
nice tank, but i would have gotten atleast an 8ft tank for 500gallons.


Looking forward to the build!
 
its someone else's 1 year old custom tank, and since I'm not paying something like $5k for it, I won't complain :)
 
I'm trying to put together components and would really like to do this as a FOWLR right now and then reef in a couple of years. It seems to be that purigen and a protein skimmer serve the same purpose, is it feasible to use 2 FX5's with biomax and purigen to work in a fowlr?
 
You must log in or register to reply here.
MonsterFishKeepers.com
Top Bottom