Backyard Aquaponics
A place to discuss aquaponics

I am considering building a rearing tank from 4x4s, 3/4 inch particle board, and a liner. Basically I want to build a frame out of 4x4s, sheet it with the particle board, and put in a liner. A 6x9x4 would hold 1620 gallons. Figuring 80% fill, that comes out to roughly 1250 gallons. Would the 4x4 frame and sheeting be feasable for a tank?

Is this to be indoors or out? Partical board will not hold up well outside. Also you might have trouble finding partical or ply 9 ft long. That much water will also weight a lot - probably in excess of 5 tons. If the 4x4 are to elevate it, you will need a lot of them. If on the ground, you will still need a lot of bracing just to hold it together. IMO - I would rethink building materials for something that size.

Hi DWilson:

Have you tried googling plywood aquariums? I would use the reef and monster fish keeper folks as a guide for plywood tank construction. I made a frame for my rectangular in-ground lined pond but that is supported by dirt around it. If it is free standing it needs to be sturdy or else...!

Will I lose tank integrity if I cut the top of a tank like this?

I have seen forum members who've left some ribs of the tank top to help with that rather than cutting off all of it.

You might consider concrete blocks. There is a pond place around the corner from me that builds shallow pond by just dry stacking concrete block 3 blocks high and lining with pond liner. I would not use the dry stack method, but they have a bunch of them built like that. My lawn guys would nock the blocks out of place in no time.

Particle board will dissolve!!!!! And I now very strongly discourage using liner against anything but treated lumber. I am in the process of replacing all my lumber and liner beds that were built with non treated wood cause the termites will chew from lumber into liner before they realize it and cause leaks.

If you get outdoor or marine grade plywood that might be ok but any wood tank is gonna have a limited lifespan.

I also agree that the size, you might want to look into making the size work with standard lumber sizes to avoid waste.
EPDM liner comes in widths of 5', 10', 15' and so on so 6' width with 4' depth would work for liner but it is a bit wasteful of lumber to make a 6' wide tank. 4' wide would probably be more appropriate. Also 8' long would be better for lumber usage.

Water is heavy, you will need bracing members across the bottom and top of the tank to keep it from bowing out in the middle of a 8 foot long tank.

Now if you are trying to save money, look at perhaps doing multiple smaller tanks. I've done a liner and fencing panel tank of over 700 gallons for the cost of a couple cattle panels, a 15' by 15' piece of liner some thin blue board insulation, a tarp and some cables/hardware or banding to keep the cattle panels in a 6' dia circle. Total cost under $300. Circles are stronger than rectangles for holding water and hold more volume for the amount of materials to frame it. Only major drawback is the need to carefully fold the liner into shape for a circle instead of the easier folds for a rectangle.
So to get the same volume you would just build two of these tanks for well under $600 and I expect it to last much better than a lumber tank would.

Of course there is also the option of using 4 300 gallon rubbermade stock tanks which would cost around $640 and be very easy to do though they are not very deep. It would depend on the rest of the system design and the type of fish that you are planning. If Tilapia, I would definitely go for the 300 gallon rubber made tanks since separating the fish by size and such can greatly improve growth rates and it probably wouldn't be that hard to get a mesh bottom to keep them from accessing the bottom of the tank. If going for something like catfish, I kinda like larger/deeper tanks though a 300 gallon stock tank would still serve for channel catfish. Those are the only two fish I have personal knowledge of so I'll let others make recommendations about other types of fish.

I have a 1550 gallon tank just like those as my FT. I cut the top out and have had NO problems. I did leave a lip about 9" wide all the way around.

Also, be aware, their water volume measurements are with the top on and the tank FULL!! My 1550 yeilded a tank that actually holds about 1100 gallons below the lower lip of the drain pipes (which have to be installed in the vertical wall, not above the lip...).

I'd say, excellent tank choice as I got mine used (had been a storage tank for a health supplement company) for $200!! Mine is clear poly.. actually an opaque white, but if I were to purchase, likely I would go for the dark color to reduce algal bloom. Might have to shade heavily in Summer, but a dark tank will better absorb heat in the Winter, too... especially if getting direct sunlight.

Just my 2¢.

CB

Hi D Wilson, here's a few picts of my wood tank. Aprox 4X9X 3' ...515 gallons

Cow posts in the ground about 3' deep...20" or so apart...could use the landscape timbers...less cost. The 2x4's are just temporary to help hold posts while back filling the holes.


Used PT fence boards from HD..5/8 X6"X 6'...cut to length, so end butts are behind posts. 2X4's at top, notched the posts, so 'all ' boards are flush inside the tank.


Insulated inside 3/4 "...sloped the bottom, so 'hopefully' poo will collect towards that end.


Top rail PT 2X6X12'...adds lots of strength. Just sitting there in the Pict, installed after liner was in.


Hope this gives you some ideas....

nice one david

was it synaptoman in South Africa who used weldmesh and liner as a tank that would be a great thing to use and would be very portable too, ive seen it used as a portable grain silo but not seen it used as a tank first hand but there is no reason that it shouldnt work its circular and providing that the mesh is quite close together the liner shouldnt push through the holes

my ssytem uses the shell or an old galvanised water tank that was beyond repair ( i know cause i tried ) and a liner inside that, works a charm for me

Cheers
pete

Also TCLynx.

Yep, my current big tank is two cattle panels from Tractor supply banded together as a six foot diameter cylinder. I folded pond liner into it but for only a little more, one could get a tank liner that is already the right shape. I used a tarp and some 1/4" blue insulation around the inside of the wire to keep the pond liner from pushing out between the wires since the spaces between the wires of a cattle panel are pretty widely spaced.

Very nice Tank David, it definitely has backyard appeal

'Thanks' Delgrade.....'Thanks' BatonRouge Bill.

I was given the posts and the rubber liner. I wanted a CHIFT PIST set up. Then it was a matter of lots of head scratching......

I did get to see TC's tank. 'Lots' of water and a simple design...

Thank you for all the input!!!