Backyard Aquaponics
A place to discuss aquaponics

Couple of things I picked up when I was looking into CHIFT PIST for the school system. A few people said it won't work without running at least 90mm from the FT to get enough flow. I would raise the tank another 300 while you are at it to get it 600mm up just to make sure,save pulling it down and doing it again. At this height I would also consider making a tank stand rather than a backfilled platform, it should work out cheaper, use 250mm TP logs or larger as your legs (I would use 9 legs in a grid or 3 x 3), lots of bracing and sleepers as bearers and top. If you have access to any decent hardwood logs I can cut the sleepers on site for you if you are interested in using hardwood.

I think you will need to change your GB drains to bell siphons. If you do this (and my understanding is right) there should be no need for a timer in the sump as the system will just be self perpetuating based in the bell siphons and the sump pump float switch.

Would be a good idea to link your sumps and put the two pumps together so one acts as a backup.

So did you end up not doing the CHIFT PIST for the school system, and reverted to the traditional pump in FT setup, I must admit I did skip some of the text only pages of the system posts?
Don't really want to raise up the tank that much, still want the kids to be able to peek over the edge without climbing a ladder.

No abandoned it as I could not get enough head height - would really suit a system that uses a 4500 litre rainwater tank as a FT. Also found that the siphons I had set up at home as a trial were fiddley and probably not suited to a system that would not be looked at every day and have little fingers playing around it.

People were concerned about our lack of volume in the sump should all six beds dump at once, this concern was justified as I dumped all six beds today whilst playing around with flows and the Ebara connected to a 40mm pipe could not keep up and the 500 litre sump overflowed.

I still like the idea of CHIFT PIST if for no other reason than you are only running one pump and would have liked to use it at home. Originally I was looking at a 4500 litre rainwater tabk to do this with but got the second hand aquaculture tank cheap so plans changed. I was going to put the tank in the ground so I would not need a sump and could just run the one pump but the solid dry clay got the better of me. Now looking for a sump! If you want t sell your old one let me know.

I still say go for it but raise the tank the full 600mm on a tank stand and make it so that it is a large enough stand that the kids can use one side as a deck to stand on and look at the fish, you could even build in a seat. Also go as large a pipe as you can all the way to your GB's before stepping down to 40mm. I would have the 40mm just dumping straight into the GB and not distribute it via a ring to ensure good flow.

Thanks mate, the 90mm pipe makes sense, I was thinking it over this arvo, and with 40mm coming from the pump, I would need to peg the pump back quite a bit to stop the FT from overflowing with a smaller outflow pipe than 90mm.

Not really up for cutting a 90mm hole in my FT just yet. Might hold off until I feel a little more adventurous (I can hear the wife's sigh of relif from here).

I still plan to put the 2 x 1000L sumps in regardless, as this will mean in a power failure, I won't lose water like I currently do...

Cheers for the other advice, I plan to build another 3 bed system soon, so I might give it a go then, and that's what the 500L sump is going into, sorry...

Build update...

Below are some pics of the additional wall support mountings.
I cut out a section of a T-pce, and snapped them onto the structure.

I have also managed to get the new dual 1000L sumps in also, and I have installed non-return valves on the pump lines ready for the back-up sump pump.
Moved the SP into my 1 bed system, ready for the trout on Friday .

Hope to finish the end structures off this weekend, then should be ready for the cover.

Finished the poly tunnel frame on the weekend...

Couldn't wait for the weekend, so put the roof on last night.
The split poly seems to be doing the trick holding the film, but I might have to wait for the weekend before putting the ends on (give my fingers a break).

Attached a pic from the inside view, I added a pole in the centre to help to hold the structure down (as well as the end poles) in our strong winds. The wife was waiting for the thing to take off like a kite, so even though it was bolted down, I didn't want to have to hear about that for the next 20 years, so put in the central pole. Looks like it will be a good place to mount a light also...

Got my trout on Friday, so soon all should be firing.

Looks good NF. A close up of your split poly (I assume you mean PVC) clips would be interesting. Will they create a point where the plastic will tear?

I have been fixing my wire lock channel on my tunnel house. Should get the whole thing re-covered this weekend providing the wind eases off a bit.

PVC, got me again.

Attached is a close-up pic of one of the clips...

Probably not the best option, but cheap.
Time will tell how cheap

I have rotated them around so that the pressure is less near the sharp edges (if that makes sense, hopefully the pic shows what I mean).

I tried to put the first few on by myself, but after putting a few small puncture points, got the missus to give me a hand holding the film and things went more smoothly.

The clips I'm pretty sure will be fine for the sides, not so sure on the ends yet, might have the ripping issue you mention.

Looks like it will work. If you have a marker, draw a line next to the clip so you can see if the plastic slips over time or stretches. If it slips you could put some silicone in under it to help hold it in place.

Silicon, Duffs tool of choice I have noticed

I actually used your idea for sealing my drain that joins the 2 new sumps. I didn't want to glue permanently, so used your silicon method. Lucky I did, as I didn't use enough seal tape and had a slight leak around the drain hole, so had to pull apart and re-do (put some silicon in the thread also second time around, no leaks now ).

Worked so well, I patched up a few other dripping grow bed drain joins I had been meaning to get to.

Teck screws are my choice of sticking things together. A tecky may help hold the clips in place??

Don't think they will be moving far Rick, I have the skinned finger tips to prove it...

I just split the PVC with the jigsaw, and didn't remove a section (like I did for the frame T pcs), so they are snapped on pretty hard. I made some of them from some old PVC off-cuts I had, and these were extra rigid, and really hammered the hands getting them over the frame.

I used the same diam PVC as the frame (40mm) so they are snapped on very very tight.

I made clips like that to hold down the plastic for my ice skating rink. It was helpful to round the corners to keep the corner points from digging into the plastic.

That was my original idea (rounding off corners), but got a bit rushed, and only did a few like that.

I think I'll need to do that for all the end sheet clips though.

Looking good NewFarmer...