Backyard Aquaponics
A place to discuss aquaponics

I just reconfigured all of my systems ... to the pipe within a pipe idea ..

So reliable it is unbelieveable.


OK .. I guess I have to draw it!

Gimme a while ... to do that ...

this is so very reliable if in-out flow rates are properly balanced.

I am using a tall white bucket and some short siphons in the grpwbeds... ... and have found that the taller the better ... will work every time ..


so I may rethink my system .. maybe use a big tall tank with autosiphon as a header .... when it breaks it floods everything quickly ...

I am thinkin that if the beds are configured to flood .. (small bore outlets at low level and have large bore outlets to direct the "flood" back to the main tank)

Then one big header tank would do it...

I think it is a question of "balance". ..








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Great work Ell.... Have you tried using small pipe diameters, my syphon drain outlet section is only 20mm pipe and it works a treat... If I'm understanding this correctly, you'll run into troubles because the water will take too long to drin through the gravel and into your outer 90mm pipe to keep the syphon going when it's in a dump phase... You need to take your exact syphon your working on and shrink it all, while at the same time perhaps making your outer 'gravel stopper' pipe larger, perhaps 160mm.

The water doesn't have to be drained from the grow beds particularly quickly, a slower syphon would be ok....

Thank you EB.
Welcome back to west!!
We know it is the best!!

Thanks for the comments,I think it might have been my over active and tired mind at the time, when doing further tests it was quite obvious that I had put in enough holes on the outer pipe but in the wrong position – needed more water access at a lower depth, so back on track again.

One of the thoughts was to decrease the pipe size to 20 or 25mm but will stay with the 40mm for the time being, what I am trying to do is work out the outflow using gravity then from there the maximum pump flow rate, here are some calculations:

Times from the tests where 80 litres was drained in 45-47 sec = 100 l/m or 6,000 litres/hour, by adding an air tube to the down pipe decreased the volume through the 40mm pipe to 5,000 l/hr, these are the maximum flow rates that a 40mm pipe will pass using gravity feed of about 1 metre.

Pump size:
Using 3,000 l/hr in-flow to 6,000 l/hr out-flow (and some rusty calculus) the cycle would be 90 seconds to fill grow bed and 90 seconds to drain, this I would think would be the maximum ratio using one 40mm pipe.
1,000 l/hr pump would give a cycle of 5 minutes in and minute drain and with the air pipe version a bit longer, so there is a bit to play with by using a pump rated @ 1,000 l/hr to a metre height – so the next step is to get a pump to run continuous and test this auto siphon idea properly.

If problems occur I'll just modify


Les

Sounds good Les - will wait for you to work it out .

I will be wanting to use a syphon for my Murray made bed - hopefully employing my existing 2000lpm rated pond pump (which I expect probably pumps less that this, particularly at about 1 meter head (which is the height of the bed). I expect the bed will hold about 200 litres of water between the gravel, so sounds like the pipe diameters you are using would be good for what I have .

vb - looks like this weekend is sorted out for me too.

On another point, there has been reference to picture size, I have sized mine to fit my screen before attaching so that I can view them without having the scroll bar showing up, but this may not be okay on other computers. I can size smaller if it is required

I hate those scroll bars

Les

just a quick update,

Purchased pump, rated @ 2,000 lph with max head of 2 metres, the pump has a sliding scale to adjust the flow rate so did a test measure for 6 minutes:
Fast: 69 litres = 690 lph, Slow: 610 lph. I used 10mm pipe and I think the manufacturers figures may have been rated on 20mm outlet, this would probably bump the output up to 1,000 lph or more but can check that at a later time, I have what I need to hook up and run.

Quick figures @ 690 lph: fill 7 minutes, drain 75 seconds (in theory).

Run the system and full cycles just over 8 minutes, put on the 90mm covering pipe and the cycle dropped to 7 minutes 40 seconds so definitely need a larger size pipe.

Reduced the flow rate to 400lph and still works, but any lower starts to have false starts. I have done a few other tests and modifications, which I will list but getting caught up in father’s day celebrations so will update in the next day or so.

Getting it bad – started designing the next system…….

So the siphon works Ell?

Hi VB,
yes it works a treat, I don’t know what suburb you live in or if you travel out to Burpengary/Caboolture area but you are more than welcome to drop in and see it in action, just PM me.

Need to gather my thoughts on changes made and pitfalls to steer clear of and will post a more comprehensive report on its workings.

Ell

Modifications:
Put in a reservoir tank so as to have a constant water level.
Cut down pipe length so that the end is approx 5mm below the water level.
Filled in the hole(s) in the end cap – not needed now the down pipe is not submerged by 100mm+.
Increased size of protective pipe to 150mm.
Originally had one 40mm pipe from reservoir to fish tank but nearly had water flowing “over the gunwales” (nautical term for Murray) so put in a second, water rises to top of 40mm outlet now.
Put in taps on pump outlet to adjust water flow – this is used to find minimum pump flow for siphon action and is only temporary.

Tests:
Flow rate in picture is 400lph this was left overnight and is still working very reliably.

Removed siphon pipe and allowed water to rise and overflow into the drain pipe and settle to its normal level, then placed siphon pipe back over drain pipe, the water ceased to flow down the drain pipe, the water level outside the siphon pipe rose to the height of the lid and then the siphon kicked in and dumped the water out of the grow bed.

3mm tubing works fantastically in aerating the water flowing into the reservoir (as shown in the pic) and sucking in air to break the siphon seal, further aeration from the two outlets to the fish tank.

Next step is to add gravel, this will have another added advantage as the water level in the grow bed will increase at a faster rate which will mean that the pump flow can be decreased to probably 200lph and still work – it is the rate the water level rises to overcome the siphon action of the 3mm tubing (it starts siphoning when it becomes submerged) and any spill down the drain pipe.

Add another grow bed, this will have its own 40mm down pipe into the reservoir tank.

Put in a more permanent piping system from the pump.

I have probably done more in-depth testing than is required but this was something different and so I wanted to make sure that the idea was workable.

A smaller drain pipe could be used as long as the siphon pipe is 50% larger (e.g. 20 or 25mm drain pipe to 40mm siphon pipe).
A larger air tube (I used 3mm) could be used but a larger pump flow would be needed to overcome the siphoning of the tube.

With the 150mm covering pipe, I cut out “crenellations” of 150mm * 10mm with three 20mm wide pillars to support the pipe and then put in some vertical slits 60mm * 10mm and will pack larger gravel around the base to allow easier water flow to the siphon.

I think I have covered everything, if anyone is unsure just ask – now for the pics

more like thinking of another forum member and how he could could put it to personal use

unfortunately (for Pyros) the air tube being inserted into the down pipe proved to be more reliable

looks great - very neat and tidy looking system indeed!

Great work Les.

I was at the irrigation place across the road from B on Saturday. The guy wanted $9 for tank outlets. I think your idea is better.

Have you found a suitable pvc fitting with a nut arrangment for the 40mm outlet?

thanks Am, Yes - its starting to come together quite well

BR - found these connectors in "B" 40mm DWV male & female, I put one set in the grow bed shown in pics and this is for the 2nd grow bed - cost is $10 for the set.

Sealed with silicone and it is very sturdy, before when just using silicone only had a slight leak with all the moving and pulling apart so definitely worth the effort to install, no problems if you want a look at it any time - need to stay on your good side so I can scrounge some fish off you later

Les

My 'B' store did not have those!... I want some toooo!!!!!!
Oh well, better find some other plumbing shops, perhaps they will carry them as they are perfect for what I want in my 'upgrade' to my system.