Backyard Aquaponics
A place to discuss aquaponics

So, a friend of mine was kind enough to donate a couple of old bathtubs. Actually, he was thrilled to have them pulled out of his blackberry bushes and hauled away. One less bit of work for him.

Anyways... I was planning on using the two tubs for a sump. My plan was to plumb the two tubs together, possibly using the original drain holes with a U shaped pipe. I would pump from one tub up into the fish tank, and the two tanks would automatically level the water.

There are large holes where the original drain lever went thru the end of the tank. I've been wracking my brain trying to think of a good way to seal those holes so that I can run a higher water level in the sumps without them spilling over.

Any recommendations? These are metal tubs. Not cast iron, but stamped steel with what appears to be enamel paint on them.

Thanks,

John

There is an underwater epoxy you can get here called kneadit. It's a two part paste, you knead it together until the colour is uniform, then put it into place. They have a marine version that can be applied under water. It's good for a larger hole.

If it's a smaller hole, use something like silkflex marine version. It's like a silicon, but better for constantly being wet. Silcone won't hold up to constant moisture.

What is a drain lever?

Float valve?

Depending on the size of you system and how you plumb your pump baths can be a bit shallow for sump

It depends on your configuration but might not be a good idea.

I do have to agree with Stuart as well.

I've got a 600L sump tank, and it isn't big enough for my system, the water swings are too large with each drain system, so once it goes through 200L, it needs to be refilled again. But it depends on your system.

I've heard bathtubs make good grow beds though.

Our initial fish tank will only be 1000L (Single IBC). I would need to calculate the dimensions of the tubs. These are pretty old tubs and are quiet deep. Pretty close to 24".

The other thought that I had was to use two burried blue barrels for sump tanks. IBCs are quite expensive over here. $125.00 for non food grade, $160.00 USD for food grade. I can get barrels for 10-15.00 each.

However, Just from eyeballing the tubs, it looks like they would hold more water than a barrel and I wouldn't have to dig them down as much.

Maybe I should just bite the bullet and pick up one additional IBC for the sump and call it good.

For grow beds... I was planning on cutting 10 barrels. I'll start a system thread to get more feedback. I'm almost done with the terrible Sketchup drawing.

Beat me to it.

As I was hitting submit for my last post I thought to mention the GB option, honest.

Just one thing to note, the prices for fittings (uniseals/t-bends/elbows/valves) skyrocket when you start to use a lot of barrels - to the point that a few IBC's look cheap in comparison. You don't realise it until you start buying things, and you walk out with massive amounts of things and look at the price tag.

viewtopic.php?f=1&t=21293&hilit=uniseal
We went into it in a bit more detail there.

I'd recommend building a nice growbed. They aren't that difficult (probably dependant on your skill level though), and you'll get far more filtration/growing space, and your backyard will thank you.

Ryan's growbed look simple enough to construct (I'd think that pond liner is simpler to use than the fish safe epoxy he used, but the frame seems simple & cheap):
viewtopic.php?f=18&t=8754#p256817

Or if you're handy with a welder, have a peek through my thread, they only took me a few hours to knock up the frames.

Just one thing to note, the prices for fittings (uniseals/t-bends/elbows/valves) skyrocket when you start to use a lot of barrels - to the point that a few IBC's look cheap in comparison. You don't realise it until you start buying things, and you walk out with massive amounts of things and look at the price tag.

viewtopic.php?f=1&t=21293&hilit=uniseal
We went into it in a bit more detail there.

I'd recommend building a nice growbed. They aren't that difficult (probably dependant on your skill level though), and you'll get far more filtration/growing space, and your backyard will thank you.

Ryan's growbed look simple enough to construct (I'd think that pond liner is simpler to use than the fish safe epoxy he used, but the frame seems simple & cheap):
viewtopic.php?f=18&t=8754#p256817

Or if you're handy with a welder, have a peek through my thread, they only took me a few hours to knock up the frames.[/quote]


I've read your thread end to end :-) The frames you built are awesome. What was the guage of steel that you used to build your stands?

I certainly understand what you are saying about the cost of fittings, etc. Fortunately, I have a ton laying around, and get all sizes of PVC pipe for free. I was surprised at the cost of uniseals though. 4 bucks for a 1" seems a bit much for a piece of rubber. Much less expensive than a bulkhead fitting.

We have decided to use the bath tubs as grow beds outside of our greenhouse. We'll use a barrel for the sump.

For now, we will also start with the top of an IBC as the initial grow bed and plumb in more as time goes by. I may attempt to build a single long grow bed in place of the barrels. The only drawback is that it would certainly be difficult to re-arrange or move once in place.