Backyard Aquaponics
A place to discuss aquaponics

G'day guys, new to this and looking for some advice please.
I'm building an in ground pond (4500 litres) with IBC's as gbd's and was wondering if 25mm pvc inlet pipe (19mm outlet hose) was too big or not ? also can anyone tell me what a reliable pump will cost in perth?
Cheers

Peter

A lot depends on how you are setting up your system ....., but 25mm ,, NO , NO ,, better start thinking 75mm for pump outlet piping.
Good pumps are around $200 .

Yeah depends on your design and method of delivery to the growbeds... but 25mm is the minimum.... and a lot of pumps will have a 40mm outlet anyway...

For return... don't even think of using anything less than 90mm...

Rupe,
Why not use anything less than 90mm for return? I've got a 90mm pipe around a 40mm pressure pipe standpipe and it seems to be working fine (so far anyway, its only been running for bout a week) and then some 40mm pressure pipe to the ft.
And i'm only using an aquapro 2400lph with a 19mm black poly pipe feeding the bed (am forseeing that i will need a bigger pump in the long run, but am gonna have to run 2 pumps anyway).

Cheers
Jono

Was talking 90mm for return to sump/tank etc... but it depends on your configuration and how many beds you're potentially draining... and what method...

I use 50mm for my 4 half barrel loop siphon system... and 25mm for the delivery to the beds... mainly because the pump I use has that sized outlet...

On the mega system the pump I use has 40mm outlet that I reduce to 25mm for delivery to the sequential valve... and the growbeds...

The trout system (same pump)... I just run straight 40mm... but when completed, it'll drain through 90-100mm...

These grow beds drain into 90 mm then drop to 50 mm for the run to the sump tank 6 meters away
If i was doing it again delivery at least 25 mm and return 90 mm all the way

Thanks guys, interesting, but if i run smaller (25mm) going into the growbeds than coming out (90mm) surely the gbs will empty faster than they fill.
Do i need to restrict the outlet ?

No offense vegieman but I think you need to do a lot more reading.
Normal set up is ,, beds fill to NEAR the top ,, then a syphon kicks in ,, water is removed quickly ,, repeat repeat.

Hi vegiemann, jump onto YouTube and do a search on aquaponics - there are lots of good videos there that will give you a better understanding of the different types of AP systems, how they are setup, operate etc.

Much better idea... read through the forum here... especially the members systems...

And just keep asking any questions you may have...

Re : 25mm draining into 90mm.... it's suggested as (see F&F's pic) you are likely to be draining more than one growbed back to the sump/tank... it's used as a common drainage return rather than single returns from each bed...

Although that can be done as well... as is the case in the BYAP kit systems... but even then the return lines are 40mm (min)...

This is because of the nature of the overflow standpipe or siphons used... which drain the water from the growbeds faster then the inflow from the 25mm input to the beds...

i used 25 mm in my CHIFT PIST as the outlet of my tank and if i re-built my system i would definatly go bigger - probably 50mm,

it does work but it is slow and now that the system is gettin older im gettin build up of bio film and its slowing down more and ive never been able to get my water clear as i would like which i think is due to the water moving too slowly

Cheers
pete

vegiemann,
I hope that you do know that Backyard Aquaponics is just in Jandakot Perth. If you do already know, excuse me.

If you do not, do drop by and have a look at their setup to get some ideas. And they do sell pumps as well.

Rock Around the Block have been referred by a number of forumers for pumps as well.
http://www.rockaroundtheblock.com.au

Yep, the examples I was giving relate to a pumped system... for a Chift Pist overflow delivery to growbeds... 50mm would be the minimum IMO..

You had some confusion about how a bed could flood if being fed by a 25mm pipe but draining by a much larger pipe.
Well usually there is either the siphon or there is a standpipe and the pump works on a timer.

The trick with a stand pipe is there will be a couple small holes at the bottom to drain the bed while the pump is off but the top of the stand pipe is open just below the level that you want the bed to flood to so that the pump running a few minutes longer than it actually take to flood the bed, won't cause it to overflow beyond the desired flood height. So in a way, yes the drain at the bottom of the bed is restricted but the pipe itself isn't.

Another thing to keep in mind with pipe sizing for this sort of thing. The pipe from the pump is going to be under some pressure and the water will flow faster than the gravity drain lines. If you were to pump water into a bucket by a 25 mm pipe and install a 25 mm pipe as an overflow just below the rim of the bucket, the bucket would probably overflow over the rim since there would not be enough water above the overflow to get the water to move out the overflow fast enough to match the inflow under pump pressure.

Good explanation TCL.. (as ever)... it's sometimes easy to take things for granted... forgetting that those new to AP might not have the advantage that we have through dealing with these things in the past...