DIY Plywood Grow-out

[papibear4202]

Anyone have a DIY plywood grow out tank? I was thinking of building something like that with maybe plywood and a pond liner. It’ll be a good year or so before my “dream tank” is finished and set up.

 

[mcarroll]

Anyone have a DIY plywood grow out tank? I was thinking of building something like that with maybe plywood and a pond liner. It’ll be a good year or so before my “dream tank” is finished and set up.

Pondliner I would trust not to leak with a slight scrape of live rock is WAY more expensive than I expected....so I dumped the "plywood pond" idea. I've seen it done before though and it works well.

Maybe if you already have the liner leftover from a pond project?

 

[papibear4202]

Anyone have a DIY plywood grow out tank? I was thinking of building something like that with maybe plywood and a pond liner. It’ll be a good year or so before my “dream tank” is finished and set up.

Pondliner I would trust not to leak with a slight scrape of live rock is WAY more expensive than I expected....so I dumped the "plywood pond" idea. I've seen it done before though and it works well.

Maybe if you already have the liner leftover from a pond project?

Rock will be in the sump. I don’t think I’ll have any rock in the tank itself just frag racks

 

[mcarroll]

Rock will be in the sump. I don’t think I’ll have any rock in the tank itself just frag racks

I'd worry about *anything* sharp.....and of course frags at usuaslly "live rock" on the bottom. ;)

 

[papibear4202]

Rock will be in the sump. I don’t think I’ll have any rock in the tank itself just frag racks

I'd worry about *anything* sharp.....and of course frags at usuaslly "live rock" on the bottom. ;)

Hmm that’s a good point. It is def a thing to think about. Something falls pokes a hole, everything is gone.

 

[Dr4gula.f32]

They make pond liner epoxy which is what most plywood tanks are built with.

 

[mcarroll]

They make pond liner epoxy which is what most plywood tanks are built with.

I think that's not very cheap either, and also not that easy to apply correctly from what I've heard.

 

[UncommonSense]

I used to have a very negative opinion of pond liners, mostly because I assumed they were all rubberized material… until I built an actual pond using Reinforced PolyEthylene (RPE) liner material!

In my case, I used the thickest RPE I could find (40mil) for the main pond, and 24mil w/8mil of UV protective coating for the associated water garden… both thoroughly impressed me, honestly!

I had to lean substantial body weight on the tip of very pointy scissors to get them to pierce the liner material while cutting it to size, and ended up using a hooked razor blade to trim the liners to final dimensions after install! — you can’t even tear the darn stuff if you cut a slit in a sheet and attempt to propagate it from there!

 

[mcarroll]

I used to have a very negative opinion of pond liners, mostly because I assumed they were all rubberized material… until I built an actual pond using Reinforced PolyEthylene (RPE) liner material!

In my case, I used the thickest RPE I could find (40mil) for the main pond, and 24mil w/8mil of UV protective coating for the associated water garden… both thoroughly impressed me, honestly!

I had to lean substantial body weight on the tip of very pointy scissors to get them to pierce the liner material while cutting it to size, and ended up using a hooked razor blade to trim the liners to final dimensions after install! — you can’t even tear the darn stuff if you cut a slit in a sheet and attempt to propagate it from there!

The one I was most familiar with used (I think) two layers of 1/4" liner....that seemed very expensive when I tried to look it up.

But how much does the stuff you're using cost?

Seems like $400-$500 is the price of admission, but then you have a pile of pond liner left at the end.

Hmm.

 

[UncommonSense]

The one I was most familiar with used (I think) two layers of 1/4" liner....that seemed very expensive when I tried to look it up.

But how much does the stuff you're using cost?

Seems like $400-$500 is the price of admission, but then you have a pile of pond liner left at the end.

Hmm.

I bought this before prices on stuff got completely out of hand… it looks like the site I bought from actually took down the category since!

However, a more generic (more overpriced) pond retailer has 40mil 10’x10’ RPE liner listed for $74!

https://playitkoi.com/products/pik-koi-pond-liner-40-mil-ultra?variant=39904461979718

There’s also beefy 60mil RPE being advertised, which I wasn’t able to find a year and a half ago when I was last looking!

 

[kylejames89]

They make a pond liner epoxy that would work. I’ve seen it done a lot in freshwater

 

[mcarroll]

I bought this before prices on stuff got completely out of hand… it looks like the site I bought from actually took down the category since!

However, a more generic (more overpriced) pond retailer has 40mil 10’x10’ RPE liner listed for $74!

https://playitkoi.com/products/pik-koi-pond-liner-40-mil-ultra?variant=39904461979718

There’s also beefy 60mil RPE being advertised, which I wasn’t able to find a year and a half ago when I was last looking!

Intetesting! Thanks for your perspective!

10x10 is a much more reasonable size....worth looking at.

 

[mcarroll]

Intetesting! Thanks for your perspective!

10x10 is a much more reasonable size....worth looking at.

They cali it's really stiff o that site.....wonder if that matters for box shapes (eg a frag tank) or if that's mostly an issue with "round pond shapes"?

 

[UncommonSense]

They cali it's really stiff o that site.....wonder if that matters for box shapes (eg a frag tank) or if that's mostly an issue with "round pond shapes"?

Ah! Yes… it has ZERO give, like the world’s thickest tarp!

You end up putting it into the requisite hole shape like you’re wrapping a present; making pleated folds at inside corners to make it conform! (Install SUCKS compared to standard rubberized liners, but it ends up being a much better product!)

You can actually use specific repair tape to cut these pleats off and make sealed seams at inside corners if so-desired… the cleanest possible way would be getting one pre-formed into a box shape with ultrasonically welded seams or similar, but this is by-far the most costly option!

 

[13rodo]

Have you ever seen "Australian Aquarist? He builds massive plywood tanks. Has a whole series on it:

 

[areefer01]

Honestly - just buy a Rubbermaid stock tank and call it a day. Don't over think this. Can also serve as an emergency holding tank should something happen. Win, win.

Also not that expensive and come in various sizes. Bonus points you can buy a potable water storage container used in boats or RV's. Just cut out one top, leave 2" or so for bracing, and if required 1 x 2 frame around it for support.

Rubbermaind stock tank may be cheaper but my point is that you have options. Can also look at ebay or FB market and buy stock tanks there.

To properly build a tank out of plywood will require brain time, materials, and tools. Not saying you can't do that but only suggesting asking yourself if the juice is worth the squeeze.

 

[mcarroll]

Honestly - just buy a Rubbermaid stock tank and call it a day. Don't over think this. Can also serve as an emergency holding tank should something happen. Win, win.

Also not that expensive and come in various sizes. Bonus points you can buy a potable water storage container used in boats or RV's. Just cut out one top, leave 2" or so for bracing, and if required 1 x 2 frame around it for support.

Rubbermaind stock tank may be cheaper but my point is that you have options. Can also look at ebay or FB market and buy stock tanks there.

To properly build a tank out of plywood will require brain time, materials, and tools. Not saying you can't do that but only suggesting asking yourself if the juice is worth the squeeze.

An excellent tried and true option, but they don't come in frag tank sizes or rectangular shapes. ;)

(I think those are the main downsides for this case.)

 

[UncommonSense]

Here’s what I've been eying up to upgrade my old aquaponic system turned turtle pond:

300g, but less rounded (thus more space efficient) than a Rubbermaid 300g at ~81”x42”x25.5”


It seems like exponentially less work and commitment than a dedicated dug-in pond, and can see this shape working well for a frag rank…

 

[areefer01]

An excellent tried and true option, but they don't come in frag tank sizes or rectangular shapes. ;)

(I think those are the main downsides for this case.)

That is true.

The question comes down to what would be more reliable, reused, and cost. It is not if one can, but rather should. I know a fellow hobbyist who built a 760 gallon plywood tank that is beyond amazing. Then there is Alex G's system. So it can be done.

Rubbermaind stock tank dimensions - if they don't work just use PVC to make some legs. Rectangular is optional.

Nothing you don't already know though so not poo pooing the concern. Just adapting is all :)

SKU Number	Gallon Size	Dimensions (Length x Width x Height)
FG424300BLA	50 Gallons	52.00 in x 31.00 in x 12.00 in
FG424288BLA	100 Gallons	53.00 in x 31.00 in x 25.00 in
2226155	120 Gallons (Low-Profile)	73.50 in x 39.00 in x 14.00 in
FG424500BLA	150 Gallons	58.00 in x 39.00 in x 25.00 in
FG424700BLA	300 Gallons	63.25 in x 69.00 in x 25.00 in

 

[mcarroll]

The 50 gallon tub is one I've considered before, but due to space I really needed rectangular. The 12" depth is nice tho....Grainger seems to carry a similar brand in grey if that color would be preferred.

The shop I use to work at back in the day used the 150's for sumps.....such a narrow bottom due to the stepped sides, and when you add the round ends it's just not a good compromise since it takes up so much space per gallon. Makes sense it's supposed to be outside and in the ground. :)

(One could fit 250 gallons in the space the 150 tub takes up.)

Price-wise you're dead right tho...so if space isn't a concern and the odd shape isn't a deal breaker, then why not?