Backyard Aquaponics
A place to discuss aquaponics

Hey

what do you consider small FT's?

I have a chift pist system on a 600 gallon (2270L) tank....

my surface rises 3" (7.6cm)....

I believe that the amount of height will be determined on where and how big your overflows
are..... I have open t's on 2" (5.08cm) SLO drains and the water actually comes up to the top
of the T's which gives me the amount of rise I get....

but that is my system.. im sure everyones is set up to what works for them

jT

105 mm to the 1000L.

The simplest way for me is just my pump on a timer 15/45, and my 4 GBs draining back to my FT. The thing is, that should take 1000L at a time and doesn't do your cycling of the water properly. Then I hope to expand a little to 8 GBs in 4 banks and the water level will move by 200mm out of 500mm or so. Not that bad I guess. I could just raise the level so I was swinging between 6000L down to 4000L. I just thought sequencing the GBs made it tidy. Plus I have a control program on an old laptop and 4 or 5 radio receivers with electronic controllers and what not from our old irrigation set up that I'm sure, if I just know a robotics engineer or something, I could set up to do almost anything.

Simple is definately where I should start though.

Yep that means your drains are too small to gravity feed the amount of water you're pumping in. Once your FT level reaches the top of your drain (horizontally) you actually have a siphon going.

As you rightfully pointed out the larger the drain the less your FT level will rise also.

Dexter there is no problem overflowing the GB's once full. Once the GB's are full the water simply overflows the standpipes and makes its way back to the tank. Trial and error on this forum seems to have shown flood and drain cycles have little effect on plant growth, so long as there is a flood AND a drain cycle (where the roots can get exposed to oxygen) then it seems to make little difference if you do 15/45, 30/30, 30/45 or 60/60 for example.

Yes I have a by-pass which puts the excess water the pump puts out back into the ST...

reasoning for the setup was I planned ahead to expand the existing system...... which will
take place this spring when I double the existing GB area...

jT

Training new staff

Hand my new engineers the plans.....

The dream job. Site supervisor.

Voila!

ah yep, they wont be going anywhere Very nice.

Yep, no way they're gunna bow... mind you the whole bloody thing might sink into the ground ....

I put it on stumps. Takes away the pressure of having to get the ground level.

I'm rummaging for the receipt but I'm pretty sure the steel was just over $300 and I had a bit left over. Add the price of the tubs and it rounds out to under $600 per 1000L set up. Not to bad but I thought I could do better. I have the odd broken green treated post so I thought it use a few up and make a timber GB stand. The sides bowing out remains a proplem here, as opposed to my steel frame design, which solves it neatly.

http://www.holmanindustries.com.au/prod ... 20Splitter

I wonder if this can help me? I want to run my pump constantly and sequence 4 or 5 valves every hour. Garden controllers don't seem to be able to cope with turning on/off more than 4 times a day, so I'm told. Surely this is not that hard?? I have xmas lights that chase one another around all night. 4 valves, 15 minutes for each turn, 1 hour till its back to the start. I should nearly be able to make my own using bits of kids toys!!

Not a bad Idea but would probably be fairly expensive as you need one on each controller output,
would probably be cheaper and more user friendly to go for a more expensive controller that allows more starts per day - the holman commercial one here http://www.holmanindustries.com.au/prod ... duct=PRO46
allows 16 starts a day so that gives 6 stations 15 minutes 16 times and as long as my maths are correct thats 24 hours.
the bigger commercial ones from the same site (and most other brands commercial units) give lots of starts a day so would allow 3 or 4 stations to cycle through the 24 hours.
The programming for a single controller would be a lot more simple too as with the auto splitter you highlighted every time you run the controller manually to check something out or change the station time the splitter will go back to learning mode and cycle all the stations for a minute each until it learns the cycle again. I think it would make it fairly difficult to get the fill times right initially. They do have a programmable one instead of the auto one and that may be a better bet if it works out cheaper than the pro controllers.
John

If you know a good Electrician (like myself?) you can use a small PLC (programable logic controller) with a number of relays to control pumps, valves or what ever? I build small units (4-outputs) to control pool pumps over a whole year changing the pump run times gradually to suit the season (pays for its self in power savings). With a PLC there is no limit to on/off times and you can incorporate other devices into the control system such as float level switches etc. Basic unit with 8-inputs and 4-outputs cost about $300.00 including enclosure.
In regards to your fish tank I think you will have problems down the track with painted steel, maybe using a PVC fish pond liner in the tank will work better?