Backyard Aquaponics
A place to discuss aquaponics

As I understand it from reading your posts, you plan on running ~1500L water above the venturi drain line in your main FT and keep the sump tank empty (or relatively empty) by running 2 sump tanks, the 2nd for redunancy purposes.

What happens in the event of a power failure? FT will continue to fill beds until water drops to venturi drain level, beds will fill then syphon to the sump. Sump being only 500L, 1000L will spill out of the sump?

Correction.

A 5min timeout on the edit-a-post feature would be mighty handy. Not even Conroys censorship plan will be this strict

This was discussed at school, tank would be filled back up Hopefully the fish will still be alive, plants might have dried out - this is one of the benefits of bell siphons over Joel's drains, we figured that most beds would have some water in them so deep rooted established plants would survive.

In all I guess this is another advantage of running a timer system be it pumped from FT or via venturi - starting to look like we might have to pump

Longer term we are going to have to consider a backup power option as well but at the moment there is so much more to do so it is down the list.

Maybe a wind powered water wheel.

Longer term I want to make a cycle pump that is mounted next to the FT that the kids can ride at recess and lunch just for the fun of it. It will just recirculate water in the FT, maybe via a nice bell fountain or something. Or maybe two of them that feed into Japanese tilting buckets over the tank and they can race each other to get the bucket to tilt.

Hey burnsey,

so much effort and you are ignoring backup power. A simple Jaycar module can solve your problems by turning on a 12 volt pump when the power fails, even if all it does is circulate water around splashing in the tank. Cost about $110 with a battery that will runit all for 5 hours and an automatic trickle charger.
12 volt pump could be located in the sump to stop it overflowing when the power fails and your growbeds are full. If your sump is the lowest point in the system, and your growbeds hold 1200 litres of water, and your sump is 500 litres, I can't see how your fish tank is going to be filled up? What am I missing? The only thing I can see happening is 700 litres end up in the dirt
Also, really think hard about having a sump that can take the whole volume of the flood. It will save you mega dramas in the long run. I sort of understand what you are trying to achieve, but really think that if you are doing chift pist, you need the sump to be the volume of the flood water required plus a bit for the pump. I may be wrong, and I may have missed something. It will be interesting to see what happens when you turn it all on. I hope it works for ya.

Could try an Archimedes screw. I so want to build one of these and run it off a windmill, just for the heck of it.

Monya, not so much ignoring it as just needing to get alot of other ducks in a row before I tackle it. We won a Stepanie Alexander Grant to build a kitchen garden so the aquaponics system is one part of alot of things that I currently have my finger in as well ass classroom teaching. There is currently a full classroom kitchen and dirt gardens being built as well, all managed inhouse on a very tight budget.

The essence of the system I had planned was not true CHIFT PIST as the fish tank would not be constant height. In the end I think that our venturi pipework may not be large enough diameter and our FT to GB head may not be enough to pull it off so we might be just sticking with the boring old norm - pump in FT

Put down the second deck today with the kids, erected the first grow bed stand and picked up the hydroton. The blocks used to support the grow bed were alternatively orientated to remove any chance of them racking or being able to be pushed to collapse, the 100x100 bearer across the blocks was also bolted into them with 150mm ramsets.

Another half days work and it will be ready to be turned on with the first two beds.

Quick shot of the results of the days work, there will be lots more photos on the school web I linked at the start of the thread showing the extent to which the kids have been involved in the actual construction, you will have to wait till after school holidays for the next web update though. In essence they have been involved with every part. Yesterday they measured, I cut then they put together the grow bed water distribution rings before marking them out and drilling the 6mm holes all the way around them. The entire of the second deck was laid by the kids by themselves today before I came along and screwed it all off. The correct deck we used although expensive is very kid friendly and has the added bonus of being easily lifted if we ever need to make major pipework changes.

It's getting closer...

Burnsy ..

You are inspirational!

Thanks for the comments, it is a great project to be given the chance to complete. Few more hours with the Principal helping out today and we got two GB's plumbed and filled with water. No water in tank yet as I need to get some mesh as a temporary cover until our lids arrive. Put the seedings that were in my class straight into the beds in their pots so they won't dry out without daily watering - and to make them look nice

How long does it usually take hydroton to become saturated and stop floating?

Cheers,
Mike

Blimy, how many bags did you put in each bed...?

Or is that floating up.

I'd normally put only 500L in, and generally you are only ever filling to an inch below the surface, so the clay never really floats.

Only 500 litres (10 x 50 litre bags) in each but the drains currently have a plug in them so we could overfill the GB's with water to get the hydroton to saturate so it is floating up - feels all nice to stick your arms in It settled quite a bit while we were there but figured there must be a saturation point for hydroton and wondered how long it took to reach that point. Also wanted to put lots of water in the beds to make them heavy in case inquisitive holiday makers decided to come have a play tonight We will keep them full until I get the FT pump plumbed up which now can't happen until Tuesday when I can get a lockable electrical box and timer for it, after that it is full steam ahead and I will put some Koi in to start it cycling before the trout arrive on the 1st.

Just like rice bubbles...

I doesn;t really all get totaly saturated, But like I said, doesn;t really matter, it all sits solid when you're flooding and draining for real