Backyard Aquaponics
A place to discuss aquaponics

Hi guys,

I'm planning on a bigger system an would like your advise before i make a move on it.
Planning on a CHIFT PIST with 1100L FT, 1200L GB, 600L sump, (may up grade sump to 1000L to allow for more GB) Just depends on how much digging I want to do!
Planning GB's to flood & drain via Bell siphon,
Simple venturi drain to assist in removal of solids.
Attached are some sketches, but I would much prefer to keep all the GB at a constant height, with ballvalve to control the amount of flow to each GB.
or is it better to stagger them?

Also what is the best pump to use and how many litres per hour does it need to pump??

regards
Matt

Photo 1 is the best its almost impossable to cascade 4 grow beds using bell syphern

thanks FF,

I was hoping that some one was going to suggest that. Like I said I really want the GB's to be at the same height draining to the sump.
From memory I have a 300l GB that has about 400 LPH to activate the bell siphon (running constant.) simple maths says that I require at least 4 times that. So 1600 LPH min?? Or is there an easier way??

Anyone know how to insert a sketch up doc in the the forum???, got one for you guys but have no idea how to get it on here?

Regards

Matt

Think you need to save or export it as a "png" document... then attach...

Hi Matt - unless you want a really big sump then your only options with your CHIFT PIST system are:

- half the sump size required by having two sets of cascading beds (ie two beds in each set)
- have some sort of alternating device fitted. People have done it using actuators and the like, but this is not a simple matter and can be prone to failure. Rupert is marketing an alternating valve - but only he could advise whether it might be suitable for your application
- run at least some of your beds continual flow instead of flood and drain
- run some of your beds constantly flooded (this is not as silly as it sounds - I have done it quite succesfully, though it does rely on a reasonably high turnover of water to ensure sufficient oxygen levels in your flooded beds.

Good points VB Just remember kiss [keep it simple stupid ] my whole system runs off 1 1000 ibc [been doing that for over a year now no problems ]

Yep - my responses are based purely on Matt's stated desire to run continuous with CHIFT PIST.

here is some sketch up drawings.

Also got my first system as a nursery tank up the back.

regards

matt

I'm hoping to run all beds level, is there something wrong in running pump 24/7 with the GB's on bell siphons?
Looks like i'll be running a 1000L sump so incase the boss let's me expand, may even run some yabbies or some other crustation in it. so whats the deal with Marron or Red claw? can they be grown successfully in VIC?


Regards

Matt

Matt - I'd misread your original post. Where you were talking about pumping capacity, I thought you were talking about how many litres it would take to fill all the grow-beds. With 4 x 300 litre grow beds at 60% media displacement (therefore 40% water to fill) you'll only use 500 litres, so your sump should be fine and provide plenty of capacity for some water drop between top ups.

Looks good, Mattyry.

Unless I misunderstand your question, there is no specific flow required for a bell siphon to work, one just needs to size the siphon for the flow available, whether that is 1lpm or 100lpm. I tend to oversize things, then add a reducer at the bottom of the outflow. I wonder if one could use a ball valve there and really tune things nicely?

Rather than use ball valves at each bed, one could have a pvc elbow that one could turn up to reduce flow, flat to increase it.

I found a few different mods were useful when getting my autosiphons to operate in a bullet proof manner. This link shows one of the mods I used:

http://www.backyardaquaponics.com/forum/viewtopic.php?p=105434#p105434

Having the bends can help a lot in getting the siphon to kick in, but can also cause problems in getting the siphon to stop. This helped with that (by assisting air to get into the pipe) and the elbow also obviously helps to direct the water downwards into the sump. The water only comes out of the cut out bit with force at the start of the siphoning.

Until I changed my beds to continually flooded to increase the amount of water buffer I have in my sump while I am not running my system stocked (therefore reducing the frequency of need for top-ups) I was running my siphons for over a year without hitch and I didn't even clear roots or clean them once in that period. My beautiful bella (the big bitch siphon - probably only remembered by some of the old crew) meant that I was able to have a horizontal run of over a meter of pipe to the sump from one of my beds and still have the siphon kick in and stop without issue.

Good Plan Mattyry

Only suggestion I would make is if you have the time and the patience, dig a big hole and have a big sump.

My system specs are similar to yours, 1100 litres IBC fish tank, and 3x500 litre grow beds. My sump is an 800 litre IBC.

To be honest I wish I had made my sump another 1100 litres IBC. Not because I need more water for the grow beds but because it would extend the time between top ups. With lots of plant and hot weather the water really gets sucked out of the system so the more water you can store the better.

I run a 6000 litre an hour pump on my system. Not exactly sure what it is pumping at the head I have but rough calculation would be:

3 grow beds at 150 litres each flood = 450 litres

Each beds floods roughly 4 times per hour so 4x450 = 1800 litres per hour.

So I turn my fish tank over nearly twice an hour.

Hope that helps.

Thanks for the info FF,
I'm planning to put an IBC for the sump, but the only thing that is an issue is, that my AP site has an easement below it and I not quite sure how much digging i can do!
didn't stop me buying 4 IBC today, Drove from Mornington back to Melbourne stacked pretty high, Lucky I had my brothers motor bike trailer which had a couple extra tie downs. The price was worth the drive.

check out the photo!

regards

Matt.