Backyard Aquaponics
A place to discuss aquaponics

Agreed Stuart
Plus, those tank outlets seal very well. I have used them in pond liners, plastic tanks and glass tanks alike, and always with the same result: If done up tight and not fiddled with, they never leak.

Drilling/cutting the holes is a pain though - especially when you get them in the wrong spot!

Stuart look at my tank outlets

+1 not worth the risk.

One word, Uniseals

But what is a hobby without the excitement of "what might happen"?? j/k. I agree with heating the overflow or water near it and doubling so you have two overflows. Makes things more modular that way. You still get the tinkering element with the external container and overflow tube, plus the main container is left unaltered for future duty as another part of the ap system or something else around the house. We'll see how that turns out when I get around to my bigger system though. I'm using a 1/2 inch pvc overflow in my small system now, but that's indoors.

Personally I like uniseals for anything I can cut a hole in.

Yes i have 3 50mm (2 inch) uniseals in my system and they are great, however i would not use them on anything under about 6mm (1/4 inch) wall thickness. They are an awesome product and even my aquaculture tank was designed for them.
No holes overflows im not keen on after 220 dead fish and 300l of 5ppt salt spilled everywhere in one evening.
+1 uniseals
-1 no holes over flow

Although not a 'No Holes' system if set correctly I find over flows to do an outstanding job.
That is why I thought I would trial this one in my latest system trial.
This is a manual system at this stage but can be converted to timer.


I still have to extend the suction from tank via an outket extension

Gives a good indication as to the water quality in the FT

Overflow plumbing furthest hose is delivery to tank, front is return to filter

Filter box catches heavy solids prior to entry into ST/FT

Overflow returns to ST/FT via plumbing concealed below GB deck



Where the tank is at this stage


Point to remember re system failure:
Ensure that the drain pipe is mounted at a lower point than the delivery, this allows excess water to exit the FT via natural level adjustments.
p.s sorry to hyjack the thread!

Despite having never used them, I'm not a uniseal fan.
Tank outlets ever time for me. Nice, tough, with broad rubber washers, good thread, rigidity and certainty that it wont ever leak.
Uniseals look just a bit to easy and flexible to me. I really need to buy some to convince myself otherwise

Yep that how i felt even after spending 30 mins trying to push a 50mm pipe through one but seriously dude these things are mad. Tight as and if you look at one closely you can see how they work. They are in someways superior to bulkhead fittings as they can retain some flexibility and also don't end up with bulky screw fittings on both ends. Flexible and water tight is a winning combo IMHO.

I have a 5' tank in the house with bottom hole fittings that I am forever repairing or emptying bucketed leaks.
The back of tank system gets my vote hands down everytime. As for the fittings, these came with another tank I was given and I have adapted this smalle tank to fit.

The rubber seals on these unit are a very long lasting material with outstanding leak resistance.

As I said before, one of the main things I like about them is the fact that if the in and out system is installed correctly, there is no possible way for the tank to over fill provided the flow rate from the pump is regulated in some manner to prevent excessive over fills. As far as the 'Black Out' scenario is concerned, when the power goes off the tank water falls to the lowest point of the drain outlet and therefore your fish, yabbies etc, have water to survive.

Let's face it, I would rather have a wet mess to clean up, than a load of fish to dispose of what about you?

IF I could have I would have used the nylex bulk head fittings first off. However the biggest one available is 2" and since I'm running 100mm pipe to ensure that I will be able to drain things as fast as I want they were not ever going to be a viable option.

My GBs are made from cool room panels and E section roofing iron with a pond liner. Even if uniseals work with a liner I don't know how I could be confident that the edge of the hole would be smooth enough to not cut the seal. On top of that the diameter of flat surface required for a uniseal to suit 100mm pipe is not available in my tank. I could do a series of 50mm holes and plumb them into one 100mm pipe but that is probably going to be expensive.

FnF I had a look for pictures of your fittings but I havn't found them yet.

On my pond liner the uniseals have been working well. Where I have used the uniseals with the pond liner they are going through the pond liner and 1/2" plywood. They seem to be working just as good as bulkhead fittings for the purpose and don't require extra fittings on both sides.

I have also used the uniseals through all sorts of plastic bins with no problem and I even have a 1/2" pipe plumbed into the side of some 1 1/2" pipe using a uniseal though I have occasionally seen some dripping from that location when there is stress on the 1/2" pipe.

Stuart,
There are at least 2 brands of Threaded Tank outlets readily available in Vic. I forget what they are. I had thought they cam bigger than 50mm.
Upon Googling I found http://www.irrigationwarehouse.com.au/category223_1.htm
on here they have 100mm TOs they're really pricey, but then, retail for these things always is. Perhaps if you found somewhere local, and got them to source some they'd not be so much. I'll ask my mate at the local pump shop what the best deal is and get back to you when I can (prompting may be required)

Get your hands on a uniseal kuda.... get converted