DIY Above-ground Turtle Pond

[seanarino]

So, I don't have the room for a 300 gallon Rubbermaid stock tank just because it's very "round" - I have 4 red-eared sliders and 1 painted turtle that desperately need an upgrade. I planned on building what is basically a plywood aquarium without the front panel so I don't need to worry about silicone. It's going to have a wooden frame on the outside and plywood on the inside.
I don't know how to build this, because the tutorials are all for aquariums specifically, with the front viewing panels. I'd like some advice with a couple hangups I may have. This is the planned measurements in inches and US gallons:

Length: 96"
Height: 24"
Depth (front to back): 36"
~359.1 US gallons

The things I'd like to ask about:
- Are there wood stains / sealants that are waterproof and safe for turtles? For the wood on the outside.
- Is Liquid Rubber NeoPond any good? I don't want to use a pond liner if I don't have to, they're very crinkly and ugly.
- Should I build a DIY filter? I've been eyeing a 32 gallon brute trash can. If there's a NON-VIDEO tutorial on building one of these filters I'd like to know.

 

[jjohnwm]

I've built a number of plywood tanks of those exact dimensions; have one in my basement now. You don't need any kind of frame; building a sturdy box using 3/4-inch plywood held together with glue and screws is completely sufficient, even for an aquarium filled right to the top. For turtles, you will likely be filled to at least a few inches shallower, so even less pressure to worry about.

You can waterproof the interior with a number of different epoxy aquarium-safe coatings. Pond Shield is popular; my most recent build was with an Interseal product that was also very effective. I've also just recently started to experiment with EPDM pond liners. If you work slow and carefully, they can be laid out very neatly and look very professional...or so I am told. Mine looks like crap! But it is completely waterproof. For turtles I think I would stick to an epoxy, simply because I can see one of them taking an experimental bite of a liner fold somewhere and creating a leak.

When you build the box, you will want to Euro-brace it all the way around the top edge for rigidity and to prevent bowing. A 3- or 4-inch strip all the way around the top edge works nicely. You will also likely want one or even two cross braces spanning the top opening from front to back.

When you apply the epoxy, make sure you follow the instructions regarding mixing, application, re-coat times, thickness and number of coats, etc. Most of the problems that occur with epoxy seem to plague people who just know they are smarter and know more than the manufacturers of the products they use. They're not.

Coat the entire interior, as well as the bottom, top and all the exposed edges of the Euro-braces and top crossbraces. Some people also coat the exterior of the box, but this is a lot of unnecessary expense and also makes it difficult or impossible for the wood to dry out if somehow water does make its way into the grain structure. I much prefer to either stain the exterior wood, which "breathes" and allows water to evaporate. You can also cover the outside with cloth panels, wall panelling, etc. or even leave it bare.

A carefully-applied coating of epoxy, laid down on a carefully-assenmbled box with perfect tight joints, will be waterproof all by itself. But it costs almost nothing to get a tube or two of silicone aquarium sealer and run a bead all around the interior...all seams, including the ones under the euro-bracing and crossbraces. Takes a couple minutes, adds immeasurable peace of mind.

Of course you should built a filter! Lots of threads on MFK with plans and ideas, you need to make a bunch of decisions regarding the type you want. Most will require drilling the tank and installing bulkheads to which you will attach hoses or pipes to plumb the tank to the filter. That's another benefit of epoxy over liners; much easier to drill holes anywhere you want and quickly install a waterproof bulkhead. And as long as you're at it...install one or more bulkheads that allow easy draining and re-filling of the tank without carrying buckets.

This will be the coolest turtle tank you have ever had. After you use it for awhile and have thoroughly fallen in love with it...drain it, remove the turtles temporarily, cut a nice big viewing port in the front, and silicone a plate of 1/2-inch glass in place, using aquarium silicone. Then it will be the coolest turtle tank you will ever have!

 

[seanarino]

[snip for length]

Holy moly, this place is so much nicer than the saltwater forums I've been on! If I asked this in any forum with their attitude, I'd get a bunch of snarky answers or just told "Google it" LOL

To answer some things you've said:
- The outer frame is actually just to make it look more finished! Just wanted to make it look pretty on the outside. It's gonna be outside and it'll be one of the first things you'll see when you walk up in the backyard!
- I'm probably going to eurobrace the insides, yes. Is there any pictures of eurobracing inside plywood aquariums that you're able to share? Same with the crossbracing.
-There's gonna be a border around the top. on one side a wall that doesn't move and on the other side a wall that can be swung down, but latches closed on the outside so the turtles can't bump the latch open.
- I don't really want to use epoxy because I've heard a lot of people have trouble with it, especially in outside applications. The NeoPond says it's fish and plant safe, and once it's cured I don't think it should cause any problems with the turtles.
- The NeoPond looks good, but it is very expensive, plus you need the primer and you need to tape the seams with their special tape. I've heard of people using Drylok for ponds (that have fish in them) as well as reptile enclosures that are exposed to a lot of heat and moisture. Some people use Drylok when making plywood aquariums! Do you think it would work if I just did 2-4 coats and let it dry for 2-3 days between each coat?
- I'll make sure to silicone the seams! I plan on using GE Silicone I to do the job for that.

 

[jjohnwm]

I foolishly assumed this thing was for indoor use; didn't even consider putting it outside. You can pretty much ignore everything I wrote.

You will indeed need to completely waterproof the wood, inside and out, if you use standard plywood. Perhaps the extra expense of marine plywood would be worthwhile here? I don't know. I have never used DryLok or NeoPond, although I helped a buddy build a tank which he waterproofed with Liquid Rubber and it worked like a charm.

I love your plan to utilize the entire volume of your new enclosure, while providing a basking area above and behind the water.

I'm pretty old school when it comes to tank building: glass, plywood, epoxy...all tried and true, low-tech approaches. I have no experience with the many materials that are now available and apparently very usable for tank construction. Maybe your best bet here would be to post this series of questions in the DIY section, where we have lots of guys building tanks by using laser beams to weld together polymer sheets or whatever else it is they do. Possibly one of these newer methods will be superior in your application?

Either that, or...Google it!

Edited to add: One comment regarding your illustrated filter: it looks like you are thinking of locating the pump in with the turtles, and having the return from the filter overflow back into the tank? I've

 

[jjohnwm]

One comment regarding your illustrated filter: it looks like you are thinking of locating the pump in with the turtles, and having the return from the filter overflow back into the tank? I've kept plenty of turtles in the past, up to an Alligator Snapper that weighed over 60 pounds. I find that they are, in general, relentlessly bumbling, nosy clowns who will damage just about anything in their enclosure with them. If it were me, I would reverse that thinking and place the pump into the filter compartment, pumping clean water into the tank and having a simple overflow from the tank back into the filter. That way, all the holes/bulkheads for the filter can be drilled up near the top of the tank for easier access and less chance of a mis-step draining the tank. But again...old school...

Maybe, since your tank is outdoors, you might consider a constant-feed drip system to change your water for you automatically?

Off the top of my head, a couple guys who likely have a ton of useful info for you would be (in no particular order) Backfromthedead , wednesday13 , thebiggerthebetter , F fishdance , and M M1A1 ; apologies to a lot of other accomplished DIY guys whose handles escape my epoxy-fume-addled brain.

 

[Backfromthedead]

I would hate to steer you away from an ambitious project like this, but if i were you i would consider polyethylene stock tanks for this situation...i do not think a plywood tank even fully coated with epoxy would last outdoors. The sun and weather will play hell on the coatings, you will get a lot of constant expansion/shrinking at the joints. It would stay together fine, but keeping it waterproof could prove difficult. With lumber frame outdoor ponds i have always seen edpm pond liners in lieu of epoxy.

PE stock tanks are pretty much designed with what you have in mind: outdoor use, durability, easy to move around even by yourself, easy to drill and rig up with whatever gear youre planning. And with the price of lumber and building materials these days i dont think you could build a plywood/lumber tank for less than a comparable PE stock tank shipped to your door.

And regarding your filter i agree with john, best to elevate the pond a bit and use gravity drains into the side sump, with the return pump in the sump sending water back to the pond. Much more simple and less to go wrong that way. In the diagram you posted I could very easily see a big turtle completely dismantling the pump....if possible best to keep all wires and moving parts out of a tank with roughhousing reptiles.

 

[ken31cay]

Holy moly, this place is so much nicer than the saltwater forums I've been on! If I asked this in any forum with their attitude, I'd get a bunch of snarky answers or just told "Google it" LOL

I had a similar reaction when I read the post. @ jjohnwm : thanks for the post I actually learned some things myself. I second Pond Shield for waterproofing wood as I've used it more than a few times already.

 

[krichardson]

Holy moly, this place is so much nicer than the saltwater forums I've been on! If I asked this in any forum with their attitude, I'd get a bunch of snarky answers or just told "Google it" LOL

God I hate that,telling someone to "Google it" in a discussion forum has to one of the worst replies ever.

 

[seanarino]

[snip]

I have red-eared sliders who were stunted from poor growth due to poor nutrition (rescues) who probably won't reach full adult size, and a western painted turtle. I said this previously but didn't quite elaborate, but I do not want to do a stock tank because they're too large in the "round" fashion and I have nowhere to put a round tank. A stock tank of comparable size, going off of the Rubbermaid stock tank dimensions, would be almost 7 feet wide (~70 inches) and a little over 6 feet long (63 inches). I have nowhere to put a 7 foot wide and 6 foot long stock tank - this also includes in the ground...
I don't want to put it in the front yard where I may "technically" have room for a rubbermaid, because the back yard is less exposed, and we've had things stolen out of our front yard before. I would prefer not having my turtles stolen, so the tank is out of the question because of its sheer size.

Technically, in terms of this it would be more expensive, but to me there's a difference between "more expensive and have the space" vs. "less expensive and don't have the space"...

Backfromthedead , jjohnwm - in regards to the filter, this is just a cursory MS Paint sketch, things are bound to change. for example, I don't wanna do something that'll have a lot of waterfall / water trickling noises - the enclosure will be against the wall to my room and my walls are really bad at blocking sound. All of my tanks inside use canister filters because the sound of water flowing irritates me (I have misophonia). If there was a way to gravity feed the water to the filter without waterfall / water noises and still have the filter function, that would be nice. I may even do a "two barrel" setup. The output is planned to be below the water's surface just so I don't have to listen to it, but I plan on putting in powerheads. I tested a powerhead previously in the turtle tank (one of the cheap AQUANEAT $9 powerheads) and they weren't able to knock it off with how strong the suction cup was.

But I figured out a solution to the filter pump part, that was so easy I didn't even remember it existed until just now.

An external pond pump with priming pot.

 

[Backfromthedead]

I have red-eared sliders who were stunted from poor growth due to poor nutrition (rescues) who probably won't reach full adult size, and a western painted turtle. I said this previously but didn't quite elaborate, but I do not want to do a stock tank because they're too large in the "round" fashion and I have nowhere to put a round tank. A stock tank of comparable size, going off of the Rubbermaid stock tank dimensions, would be almost 7 feet wide (~70 inches) and a little over 6 feet long (63 inches). I have nowhere to put a 7 foot wide and 6 foot long stock tank - this also includes in the ground...
I don't want to put it in the front yard where I may "technically" have room for a rubbermaid, because the back yard is less exposed, and we've had things stolen out of our front yard before. I would prefer not having my turtles stolen, so the tank is out of the question because of its sheer size.

Technically, in terms of this it would be more expensive, but to me there's a difference between "more expensive and have the space" vs. "less expensive and don't have the space"...

Backfromthedead , jjohnwm - in regards to the filter, this is just a cursory MS Paint sketch, things are bound to change. for example, I don't wanna do something that'll have a lot of waterfall / water trickling noises - the enclosure will be against the wall to my room and my walls are really bad at blocking sound. All of my tanks inside use canister filters because the sound of water flowing irritates me (I have misophonia). If there was a way to gravity feed the water to the filter without waterfall / water noises and still have the filter function, that would be nice. I may even do a "two barrel" setup. The output is planned to be below the water's surface just so I don't have to listen to it, but I plan on putting in powerheads. I tested a powerhead previously in the turtle tank (one of the cheap AQUANEAT $9 powerheads) and they weren't able to knock it off with how strong the suction cup was.

But I figured out a solution to the filter pump part, that was so easy I didn't even remember it existed until just now.

An external pond pump with priming pot.

Im not understanding...70" is under 6' and 63" is just over 5'...but i digress.

Plenty of companies making rectangular PE tanks, i think behlen makes one thats 8x3x2 very similar to the size youre planning. Anyways it kinda sounds like you really want plywood for this, i just thought it could save you a lot of trouble. Im not a plywood tank expert or anything, maybe ill learn some things from this build.

The noise made by your filter will depend on your design and how well you executed building it. I personally have no water noise issues from my tanks with sumps, only a low hum from the return pumps. The key to making drains silent ime is to always use a valve on the drain to regulate flow, and when installing the drains they should be situated so they are outflowing slightly below the water level in your sump. Water rushing or trickling noise from pipes is invariably due to air getting into your plumbing somewhere, you just have to find a way to set up and fine tune your overflow, drains, and return pump so that your system reaches a sort of equilibrium. Water pressure in to sump=water pressure out of sump.