Backyard Aquaponics
A place to discuss aquaponics

Warning to anyone planning a system and figuring on the grow beds with auto siphons rarely if ever kicking at the same time.

I don't know what it is but no matter what I do with my two big grow beds on the big system. It seems that they keep working themselves around to filling and draining in tandem. At the moment I even have a bell siphon in one and a loop siphon in the other. I can turn one off for a while to let the other one get ahead. It doesn't seem to matter, in a little while, they will be working together again.

Must be some sort of strange tidal function I don't know.

TC, I cant remember if your syphons are draining into the same pipe or not, but when one of my syphons start, it can kick start 3 or 4 of the others due to the pulse of air into the drain....

Same thing happens at the end of the drain, one can stop, and that kicks some of the other syphons out as well.

Yep, make sure they aren't linked by pressure or vacuum.

How long have you been waiting on them? Sometimes all four of my beds are draining at the same time and it will take maybe a day for them to drift out of sync again. It should be rare for them to be in sync but when they do it may take some time to get out of it, i.e. the system needs to be able to handle all of them at once, because it will happen sometimes.

My siphons are not connected and luckily I have the capacity to deal with Filling and draining however it happens but I have seen people planning system with the idea that the beds and siphons would not be likely to fill and drain at the same time.

I think mine finally started to get out of sync with each other but for a while there, they seemed to want to stay together (even when I shut one off for a time to knock out the sync.)

Just a thought, but if you attached all the syphons together at the uppermost part (where there is a air intake to brake the syphon action) what would happen? wouldn't only one be able to work at a time?

I don't know but, I expect that (depending on the layout) that if it worked at all, they would all probably tend to kick in together or more accurately, the suction caused by one might kick in the others, and then when one sucked in enough air to stop it, they all would stop. Like outbackozzi says.

Yes, and I shudder every time...when this originally started being stated, it was pointed out that at sometime that all would sync in and that sump/fish tank volume should be large enough to cater for all GBs flooded at one time.

Good to see others coming on line with this sage advice too TC

Obviously they are not engineers. We engineers know that if there is any situation that you don't want to happen - that is for sure the one that will. Never design for best case scenario. I wasn't paranoid until I became an engineer...

I'm a stage hand and most of us strongly believe in the version of Murphy's Law that says, "If something can go wrong, it will."

I suppose this means I'm living dangerously lately as I haven't hooked up my top up valves yet!

I have 3 autosiphons that drift in and out of alignment. I run with no sump, and the fishtank level fluctuates by about 100mm depending on how full each growbed is. It's all by design. It also means that when I'm topping off the system, I need to be aware of where the water is as I fill. Sometimes I drain all the growbeds into the fish tank and shut off the pump for a few minutes. Then I can fill the fishtank "all the way" and be assured that it won't overflow if my growbeds align.

Ah!, see that is one of the many advantages of having and using "BELL" siphons...
just remove the bell housing and allow the GBs to fill and overflow...you now have the lowest level in the fish tank - without turning off the pump.

Place bell housings back and let siphons empty GBs...now able to calculate water held in GBs (within a litre or 2).


These measurements/marks can then be used to work out the height of the water to the desired height, a minimum level can be measured when the GBs are full and then top up to that level on a regular basis

Go the "BELL" siphons

Well, I've found that there are points in favor of either bell or flexible loop. It is handy to be able to pull the loop and let it flop down and drain the bed completely on occasion. This is also possible if the stand pipe part of the bell siphon is easily removable.

I like both!!!! The clear loop siphons are fun to watch though need to be protected some from light. The bell siphons are great for the ease of pulling the bell and allowing the bed to stay full for a time when plants need an extra long drink. (I did this today as it was hot and the seedlings were drooping.)

I was having a dig at Janet

"Dig" duly noted and recorded.

Amendment 1:

I was having a friendly dig at Janet