Backyard Aquaponics
A place to discuss aquaponics

Hi All,

Hope you all had a great Xmas, i got back to the job today and made some good progress. Now comes the hard part in plumbing the bugger and getting it to work lol. The plumbing plan is;
FT- 40mm pvc from the FT gravity fed down to the GB's, as you can see a 3 meter piece of PVC will make it right accross the front of my gb's, what do you recommend on getting the water into the beds themselves? i was plannining on running 19mm flex hose from the 40mm pvc via T-Piece to the middle of the outer sides of each GB with an inline tap before the outlet to control flow. (However at bunnings today i couldnt find suitable connections/reducers to allow this?)

Siphons will be two affnan's on the inner sides of the GB's which can then fall directly into the Sump below. (construction was going to be via his you tube how too)

Pump will sit in Sump and i was planning on going 19mm flex up to 20 or 25mm pvc back to the FT, again trouble finding these flex pipe to PVC connections.

Advice would be greatlu appreciated i dont want to spend anymore until i know what i should be using.

Cheers LInc

Are you thinking of expanding?

If so I would put in a 90mm backbone and then individual 20 or 25 mm hand offs to each grow bed with taps to control flow.

I would also suggest 40mm pipe from your pump to your FT. With many pumps you can buy standard PVC fittings which will allow you to attach 40mm pipe to them.

Hey Arbe,

Expanding yeah I haven't even got a system yet but I am planning on adding one more grow bed in front of the other two but that's probably it for this system, maybe some strawberry towers perhaps. If this works well it will convince the minister fir finance and then I will do something on a much larger scale. So for this system it will eventually be three gb and some towers but that's it.

Maybe I need to go to n actual plumbing shop to get the required hand off connections.

Sorry to sound dumb but when you say backbone I assume you mean the gravity fed pipe from FT to Gb?

You will find a lot of people suggesting you use 90 mm storm water pipe and fittings for slo from ft to gbs. For two reasons.
1. Massive amount of flow therefor no risk of blockages.
2. Because its the cheapest pvc pipe and fittings.

I personally I think 90 mm is big and bulky and ugly unless well concealed. Plus I have no shortage of any size pipe or fittings I want being a plumber. 40mm has worked well for me.

I have used 40 dwv sewer pipe with 40 bulkhead fitting and male and female sewer fittings for the inlet and outlets from my ft's. Its a bit trickier going from 40 sewer to 40 pressure pipe fitting for valves since they are different diameters and not meant to be used together. It can be done though.

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Hey bndybear, yeah the fella at bunnings was going on about how it's difficult to go from 40mm down to 19/20 or 25mm, to he honest he just confused the shit out of me and hence now I don't know what to do. My preference would be to use the 40mm pipe for all the larger requirements, SLO and gravity feed and back to ft, just because the location of the system I want it eventually to look as nice as possible. If it's to technical to use 40mm then I will use whatever size but that's my preference, I was going to build the SLO as per Murray DVD where he has 2 plug and waste 40mm in the side of ft.

Yes, when I say backbone I mean your gravity feed pipe from the FT.

You can always start with the 40mm and if it doesn't work upgrade to 90mm. I think you may find 40mm wont get you enough volume to trigger a siphon (specially if/when you expand to 3 grow beds).

With 40mm from your FT I would suggest you also install an overflow pipe from your FT to your Sump - just in case.

I have a 90mm SLO/Backbone and still have a trickle of water coming from my 40mm overflow.

Hmmm, if the 40mm didn't trigger the siphons what if I pumped the water directly from the sump to the gb's and the Ft and then use the gravity feed as the overflow ?

You could, but (and this is my opinion) I would prefer to pump clean water from the sump to the fish tank, have the tank over flow via a SLO (taking the solids with it) and dumping them in the growbeds and not leave them sitting in the FT or sump.

Yeah ok, what if I went 90 mm directly out of the ft but then straight down to 40mm, would that help in creating more flow from gravity? So drop it directly 90 degree from ft but only for like 100mm then reduce to 40mm and across to gb then reduced again from 40mm into gb.

Arbe do you have the details of the connections I would need to make the 90mm SLO and reducing attachments ?

Or go 50mm? We used 50mm in our chift pist system down the back and that is able to handle the flow of a 3000K/h pump pretty well.. viewtopic.php?f=51&t=8706

Personally Id rather go with Hansen tank fittings through the side of the tank, they might cost a little more but when you are going through a thin wall like an IBC it's much safer. Also a lot easier to fit a SLO to the tank fitting, you cant really do it properly with plug n waste fittings..

As Arbe says, best not to pump from sump to GBs it's silly...

And keep everything in pressure pipe, don't go to DWV there's no need to, it just complicates things trying to swap from one to the other, they are made so they can't be matched together on purpose.

Reducing immediately after exiting the FT certainly has been suggested on this site many times as an option. I wouldn't know how well it works as I just run 90mm the entire way.

Not sure what fittings you would use to reduce as I have simply used a hole-saw to cut into the side of the 90mm pipe, inserted a uniseal and then pushed the smaller pipe in.

I will be modifying this shortly to use a 90mm T with an end cap on it. I will then use the hole-saw to cut into the end cap and use a uniseal there.

Thanks earthbound, ok so what if I use the existing 40mm to go from the st back to the ft as Arbe suggested so I can use the stuff I have now. But then use 50mm pressure pipe for SLO and the feed back down to the gb's?

Thanks Arbe, is that the general way to connect PVC to flex hose by way of uniseal?

If you think about it this would not provide you much benefit. The benefit would be kinda proportional to how much 90mm pipe you have. So if you used 10mm of 90mm pipe then reduced to 40mm, then you would get almost zero benefit, but if you used all 90mm pipe except for the last 10mm then you would get 99.9% benefit, and if you had half 90mm pipe and half 40mm pipe you would get half the benefit. If you catch my drift. Without lots of experience or a mechanical engineering degree it would be hard to guess the exact benefit without trying it.

I'm not saying you should use 90mm or not, just thinking aloud