Backyard Aquaponics
A place to discuss aquaponics

I am strongly considering using HDPE tubing for plumbing. My general question is how do you connect the tubing to the various components? Is it the same as pvc? or do you have to use different connectors? I know for connecting tubing to other tubing there is compression connections and a type of "barbed" connectors. I'm talking more about how does the overflow pipe from the the fish tank get attached for example?

thanks,

Keith

Welcome to the forum .

I think we need to know a bit more about the tubing and your system and your reasons for wanting to use the HDPE. Is the tubing clear, translucent or opaque? How is the fish tank overflow going to be setup and where does it flow to? How large is the setup going to be and where will the pump be? Your question may be answerable without these but I'm not certain you'll get the best answer for your setup without also explaining how you intend to setup - might be good to get some setup feedback as well.

Cheers

All the HDPE fitting I've ever seen have been compression style. The cost adds up quick with these, especially in the larger sizes that you'll need for decent gravity flows

Generally to join HDPE sections you use compression/compression fittings. To join HDPE to anything else it would generally be a fitting with compression on one side and thread on the other. Just about every other fitting/connection you can imagine is available with thread on it.

If you're needing to take water at a few places along your HDPE the cheapest option is using tapping saddles rather than T pieces.

When you're doing the fittings up make sure the end is cut square and that you've removed all the swarfe. If it leaks when hand tight then doing it up harder with a stilson wrench wont stop it leaking, it means that the end isn't seated correctly in the rubber seal, or you assembled the pieces of the fitting incorrectly.

Blueline/metric HDPE is measured on it's outside diameter, the inside diameter will be a fair bit less so take this into account when doing your friction loss calculations. It is overkill for anything to do with plumbing an AP system, it has the highest pressure rating of all the various flavours of HDPE

The other HDPE's (green, red, brown, no line) are often known as "rural" because it's cheap and farmers use it. They have varying pressure ratings and are measured in inches on the internal diameter.

In saying all that I have used barb minsup connections applied with a bit of heat and a very sturdy bolt down clamp on blueline poly but I wouldn't recommend it. The poly is quite rigid and not designed to clamp down and seal against a barb. I think you'd struggle to find a barb that was non metalic that would work in this situation due to the forces involved.

All my plumbing in both systems is done with HDPE, and I have no issues with leaks. SLOs go through the tank walls with bulkhead fittings, as do the GB drains, and most of the plumbing is done with green line rural grade, apart from some blue line rated pipe for the 50 and 63mm pipes, as no rural was available - 63mm fittings are very expensive! Detaching pipes is easy with threaded fittings- no messing around trying to unstick glued PVC!

Yes it was no doubt significantly more expensive than PVC (although I did not price that), but I'm not happy about the toxic manufacturing process for PVC and the potential for solvents to end up in my system water, especially when the empty pipe gets hot in the sun, so chose not to use it.

Thanks for the welcome and input!

I'm in the planning stages of a 1,000 gallon fish / 128 sq ft of growbeds - (four total growbeds each 32 sq ft). Each growbed will be just over 12 inches deep. Growbeds should be expandable to 256 sq ft according to my calcs. Of course there will be a sump as well. I am wanting to put the fish tank and the sump in the ground (or at least mostly in the ground). I'm using pond liner for the tanks. If you have ever seen Will Allen's aqupaonics setup (http://www.growingpower.org/) he does a similar fish tank in ground system. I had an opportunity to view his setup last year and it was amazing.

Looking to create a system that will be modular/expandable and not flimsy -- ie not looking to replace things in a year or two. Why HDPE? Well, I realize it will be more expensive, but frankly I just want to stay away from PVC. Probably being overly cautious and I'm sure there are people on here who can point to a dozen studies showing how safe it is but I would rather do HPDE. While I have worked with PVC before but I haven't done any work with HDPE so i'm trying to get as much information as possible before starting.

The system will be located in a greenhouse. All tubing would be opaque. I believe the pump is going to be in the sump. I'm still playing with the plans a bit so its not finalized.

One of the main things I'm not sure of at this point is how a hdpe pipe could be used for a growbed drain. I watched a number of Colum's videos including one on how he did his growbed drains. I'll be using pond liner for the growbeds as he did so I would think it would be similar. Just wondering what fitting would actually be used for where the pipe goes through the growbed floor. I'm sure there are multiple options? What I have seen so far seems both non-trivial and sometimes downright difficult. Could it be as simple as using a bulkhead fitting for each drain and overflow? Larger bulkheads are certainly not cheap but it would get the job done I would think.

Thinking about it, i would guess that it wouldn't matter if pipe going through the floor of the growbed is hdpe or pvc. It would just matter about the outside diameter of the pipe right? So the fitting used would work for either pvc or hdpe as long as the pipe diameter is correct.



thanks,

Keith

25mm bulkhead fittings and riser pipes work well for me. I'm sure there is a pic or 2 somewhere in my system threads. I'll see if I can find one.

I wouldn't be using HDPE pipe for standpipes as it will always want to roll back up into a coil.

If I were trying to avoid PVC I would use a bulkhead fitting through the growbed with a rigid irrigation riser as the standpipe (cut to length) and an elbow bsp compression fitting on the underside

I have no affiliation with these websites but they have pictures. Philmac however make the best compression fittings available in the world right here in Adelaide and I would recomend them to anyone.

Rigid Riser: http://www.irrigationstore.com.au/Poly- ... vAodtFEIng

Angle BSP/Compression fitting: http://www.duralirrigation.com.au/produ ... e-bsp.html

And in case anybody isn't familiar with them, tapping saddles:

Exactly what I have in all my GBs and WBs.

I use them for lots of things, handy bit of kit

They do come in different materials, if the first ones you find are PVC just look for another supplier, they're also available made in other types of plastic

Alright maybe I should explain that I'm American. While my wife has relatives in Sydney I have never made it to Australia.

I'm including my diagram that I have so far along with deatails. Please be very gentle as it's my first setup.

I appreciate everyone's advice and input.

thanks,

Keith

-- sorry the picutre is a bit blurry. I had to resize it for the forum.

One of the things that keeps nagging at me is the pipe sizing. As I said, I am planning on a 1,000 gallon FT. "Rule of thumb" would say I need to move that volume through the system in an hour. Pump sizing I understand. Pipe sizing seems like black magic to me. As far as I can tell the "five gallon bucket method" is about the only way to get a real handle on things but of course that's after the build so it's a little late then..

I got my sizings based on what I have seen others do but who the heck knows if that will actually work??

Keith

This might help

http://www.calculatoredge.com/mech/pipe%20friction.htm

I'd cycle the water the other way around in your system - pump from sump to FT, solids lift overflow to growbeds, drain back to sump. Otherwise all your fish poo is going to end up in the sump, and you'll need to clean it out fairly frequently - if you go the other way, it goes to the growbeds and will filter out and mineralise there, especially if you put compost worms in your media. This does mean you'd have to have the fishtank up higher than you're planning, I think.

If you want to keep the water cycling the way you have it drawn, I'd put a RFF or similar between your FT and sump, to take the majority of the solids out and make cleaning easier (much, much easier). Also, it looks like you have one growbed draining into the next, or is that just the way it's drawn?

+1 to what Mel has written.... something like this (or you can flip to suit).

you can drain beds through or you can simply drain each bed direct to sump.
going media to DWC to sump works well.

Also, for the pipe sizes: http://aquaponicsnation.com/forums/topi ... pipe-size/

(Work out how big that says you need, and then go up at least one.)