Backyard Aquaponics
A place to discuss aquaponics

Well, the remote barrel siphon experiment was a success!

The pump is running 24/7 and I have a 15 minute flood/drain cycle split almost 50/50. Roughly 7 minutes to drain all 5 GBs via one siphon.

Just to recap my design:

- 7500Lph Laguna pump - flowing about 6000Lph at 1.6m head height through 40mm pipe
- Roughly 50% of pump flow is diverted back to the sump (tap inside sump) until I build the other 5 GBs
- 6000L poly rainwater FT - outside of greenhouse to the right of shot below
- 90mm SLO split into two 50mm gravity feeds to the GBs (taps on bottom right of photo below)
- 25mm pipe into each GB (will fit taps soon)
- GBs filled with 20mm river stones (a few bucket loads to be added to GBs 3 & 4)
- 25mm tank fitting drains each GB (no standpipes) with a 100mm slotted media guard
- 50mm common drain runs into the blue barrel which is a remote siphon for 5 GBs
- Remote siphon has a 40mm standpipe which sets the water height in the GBs
- Second photo below - 100mm bell with 25mm external water break (brake?), which extends slightly below the bottom of the GBs
- 40mm drain from barrel siphon to sump has a T-piece with stand pipe which allows the siphon to "burp" as per Olomana Gardens design

I have one little design flaw. When the siphon kicks off, the GB nearest the siphon empties rapidly, followed by the next one (slightly slower), and down the line with the furthermost GB being the slowest (about 6" higher).

When there's about 1-2 inches of water left in the nearest GB it slows right down and the others catch up, like an elastic band effect. Eventually they all level up and the siphon breaks. The far GB is only "dry" for about 1 minute, whereas the nearest one is dry for about 5 mins. Will this be a problem with some GBs not draining for long enough, eg, plants having "wet feet"?

The only solution I can think of is putting a T-piece in the common drain between GBs 3 & 4 and running that into the barrel siphon, replacing the pipe that comes off the end of #5 drain, and capping that end. So the 5 GBs are merged somewhere in the middle, rather than at the end near the siphon.

Next stop: water analysis, seedlings, and Powerfeed!

What if you were to use larger pipe to drain back to barrel siphon say 90mm instead of 50

I considered that, but I'd need more reducers (from 25 to 90mm), enlarge the hole in the barrel, another uniseal, etc.

The overall drainage time isn't the problem, it's the sequence of the drains preventing them from from "equalising" at a similar rate - at least to my thinking.

Loving the build sammo. Cool fishy tank and those greenhouses look the goods. Got any idea what the life is on the polycarbonate panels.

Sammo I think you need a breather tube because of the long run, you could put a 50mm T with a vertical upright as shown in the photo just around the corner from your right angle elbow.

Hi joblow. What does the breather tube achieve if there's no air going into any of the 5 drains?

I'm a week into cycling with Seasol/Powerfeed and seeing some trace elements (pH is low not high reading). Might be time to plant some leafy greens.

Sammo I think because you have 5 GBs on such a long run you would be getting an airlock with the water flow and it would be interfering with the siphons causing the problem you mention, I had the same problem with only 3 GBs having a long run back to the sump and once I put a breather tube in it fix the problem.

The single single GB in the photo also has a long run back the sump and it needed a breather tube for the siphon the work correctly. The siphon would only run intermittently and was unreliable until I put the breather tube inline and I've never had a problem with it since.

The distance from the stand pipe back to the sump in that photo is approx. 3 metres and the water running over that distance was causing an air lock and made the bell siphon play up and totally unreliable. It would be fine for 30 - 40 minutes and then stop working and couldn't be trusted not overflow the GB.

Remember normally a bell siphon only has 200mm - 300m of pipe beneath the stand pipe and then the water is free, if you run even a single bell siphon over a long distance though narrow pipe it will not perform the same as a 200mm - 300mm length of pipe because of the back pressure.

Fascinating design. Great looking build. I like the Brake or Break question too, that's a good one. Have you been trying fixes on the remote siphon break issue. Where have I seen this design before? Outdoor system Rob's?

Hi boss, I "reverse engineered" the Olamana Gardens remote siphon video on youtube, below.

A bit of an update after 3 weeks of fishless cycling.

The first of my direct-sewn seeds has finally taken, a Lebanese cucumber if I remember correctly.



Basil and something-else (must label next time!) starting to sprout in seed raising mix.



One transplanted tomato seedling seems to be doing OK with first flowers appearing.



I took some more readings today and it looks like pH needs lifting, plenty of ammonia and nitrites with some nitrates showing, probably due to the litre of seasol/powerfeed I added on the weekend (approx 7500L of water in total).

I was going to add silver perch this weekend but I might hold off for now. Should I do anything at this stage to influence these levels or just let it go another week?

Sorry I missed this earlier Charlie. The warranty is a little vague, but roughly 5 years without question so long as you haven't used abrasives to clean the panels, after which they provide limited replacement for each year that passes, kind of like the warranty on solar panels. I purchased a shade cloth kit to minimise damage over summer months and protect the plants. It gets mighty warm inside even on mild (mid 20c) days.

Sammo,

My opinion, siphins are great, I use them, but if the siphon gets blocked, my bed become constant flood. No problems there. Ran for a season like that, and no more issues than normal, just keep the flood height below the surface of the rocks.

In summary, don't stress about cycle times or amount it drains.

I'd hold off on the fish for s bit unless you like digging holes. You need to get those nitrites and ammonia way down and probably your PH up a bit first.

Great design you must be a happy chappie
You mentioned fishless cycling what are you using