Backyard Aquaponics
A place to discuss aquaponics

The beast

Test 1- put the U-bend straight under the grow bed (with 90 degree elbows) but this didn’t work
Water level rose above the 150mm pipe (stands 330mm) and water was pouring down the drain pipe but at the same rate is the pump inflow so reached equilibrium.
Manually started siphon which emptied the grow bed but water flow decreased to equilibrium again with the level about 20mm deep in the grow bed.
Options were to increase grow bed height or revert to having “U” at the fish tank end.

Siphon now working with "U" at fish tank, level of water in U-bend is 40mm and water level in grow bed above end cap is around 30-40mm before siphon action.

Butchered an elbow so that the top is level and gives about 5mm of trapped water (as shown in pic1) – now back to siphon kicking in at top of end cap.

In pic1 I have deliberately emptied all the trapped water and turned the pump on, the “U” filled from overflow then went through the siphon “burp” ritual and kicked in.

Pic 2 demonstrates the water flow and this is gravity feed – now gotta glue it all back up again.

I think that it is best to have a separate pipe for each bed.

Yes Steve – will write it up but Dave’s caught me once so will wait and see if there are any other improvements suggested – I’m off to see about gravel now.

As they say in my neck of the woods:
"Ship It!"

Good one.

got 1/4 metre of 10mm drainage gravel/blue metal/granite today, washed 2 bucket loads thats 20 litres thats a lot more to do tomorrow...aaaaah!

Murphy had a ball with me today, firstly as I was adding the gravel, the water flow to the siphon pipe was being restricted so that the 50mm (2inches) was being left in the bottom of the grow bed – this isn’t much but after a string of profanities I saw it as a positive (to stop washing gravel) and work out how to overcome this – witness the false floor as per pic, these were 37 * 24 * 8.5cm –now only 2cm high, put them on the bottom of the grow bed, placed a 25mm boulder underneath as a support and then covered with gravel - problem solved.

This is probably an overkill and I am not sure whether I was peeved at not draining all the water or looking for an excuse to get away from the gravel. I bought 4 plastic trays, 2 for each grow bed, the one on the right is how they looked before I mutilated them, an optional extra if anyone is concerned with leaving behind about 20% of the water each cycle.

Cycle now down to 6:30 min from 13:30 min, so gravel/water ratio is about 1:1 (50%)

Murphy 2 – finished gravel for 1 bed and noticed it wasn’t cutting off siphoning properly, I had placed grow bed and 80 litres of gravel on top of the 3mm air tube = squashed tube.
Hydraulic jacks are very versatile, squeezed tube back into shape and all a goer again.

System almost there now, one more bed then fish and water testing, plants.....

Mate - you've sold out putting those trays under the gravel . Once there is substantial area of grow-bed (each of Muzza's is close to 2 square meters and I hope to have 4 before too long) then this sort of thing becomes unrealistic. Besides which, take my word, this area will end up filled up with roots.

Yeh - it makes little difference in the water level over a larger system, just wasn't going to let it beat me, the weight on top will probably crush them over time too.

Hey Ell:
I have been thinking about putting the siphon in a bucket outboard of the grow bed (like some of Johnnie's sketches), and the grow bed will have nothing in it but a full length cut-in-half corrugated drain pipe along the bottom with more holes in it (the slits can clog easily), and an outlet. I would like to be able to service the siphon or detach it or upgrade it as technology improves, without trying to fit it within a standpipe surrounded by gravel. If the floor of the bucket is lower than the grow bed then the grow bed will definitely drain all the way out.

Dave, if the outlet is located on the underside of the growbed near the edge, you can do away with the bucket (unless there is some other function that I am missing - it is late here). I can see issues having the drilled drainage pipe totally submerged under the grow media though, as if it does clog with roots or whatever you have no means of access besides digging through all your media. The vertical standpipes do take up some space, but they allow you to see what is going on with water levels etc also.

Dave, with servicing/upgrading I have only used some silicone to seal the drain pipe to the connector so it is a matter of grabbing hold of the drain pipe and giving it a twist (just did it), only thing is if you want to change size of pipe then other adaptors will be needed, the drain pipe doesn't really needed to be glued at all, worse case it will leak water into the down pipe and very little at that.

the 65mm siphon pipe can be removed at any time but better done when not siphoning water, in fact it will self prime.

I can see the reasoning for not having the u-bend stuck out in plain sight but changing the water direction too much slows the water flow rate, in this configuration it has built up a lot of momentum.

the 150mm outer pipe leaves a lot of room to get down and dirty e.g removing stray roots or blockages etc.

Drilled holes I would have thought block easier, I just put some large rocks covering the slits to keep the smaller gravel away.

with the baskets, they were a knee jerk reaction and the two I showed only covered half of the grow bed bottom - the rise in the water level was not really significant - more like a pig headed reaction from me, I get that way sometimes.

Washed the gravel for the 2nd grow bad and connected up on Sunday
Turned it on and the siphon wouldn't kick in properly

Only 2 things were different from the 1st grow bed:
length of 40mm pipe from under the grow bed to the tank
3mm air tube above the high water mark in the grow bed (thought I better check it seeing as I had recommended it)

Looked underneath to the pipe and it was almost horizontal
the water was careering down the drain pipe and then slowing down just when it was sucking in air via the air tube - hence no emptying of grow bed 2.

Raised bed (hydraulic jack) and put 40mm pavers underneath and all is well

is now a good time to start water testing?

now have twin turbo's, tried balancing both grow beds with pump flow rate but gave up, have one grow bed cycling at 4:30mins and the other 6:30

now for fish - Yes

seems like the blue metal is fast becoming our medium of choice. How hany litres of grow beds medium and tanks for your system Ell?

ah yes - well there is 2 grow beds with about 90 litres in each

and just the 220litre fish tank - didn't want to overdo it on the first go

its got the wife interested tho and they are just the right size for her herb garden.

I'll get it up and running for her then let her in on the maga-bins, green house, bulk orders of perch............ :nike:

Update
been running the system for 5 days and the siphon working great
bought 10 comets and introduced them to the tank and instructed the wife on how she should care for them

PH - 7.4
water temp 20c
all the others at zero

The aquarium place had natives (Silver,Jade,Barra) and Marron, able to supply redclaw - bit hexxy tho

My next system is in the design and accumulation stage :happy2:

Nice one LKB. Herb garden will keep her happy so you can get that accumulation going on....