Backyard Aquaponics
A place to discuss aquaponics

I originally setup my system on a constant flood/drain with a bell siphon. It ran smooth like that for about 2 monthes. After that for some reason during and after heavy rains the siphon wouldn't break at all. To correct this problem easily, I decided to put the pump on a timer and run it 30min on 30min off. That was fine by me and the tank would have the opportunity to cycle 3-4 times during that 30min window (I have a small system). This worked fine for about 2 monthes.

NOW what I'm experiencing, is even after the pump has been off for 30min and there has been no activity in the siphon for 30 min, when the pump turns on the water only fills about 1/4 of what I want it to and the siphon re-activates starting to drain WAY too early. You'd think I built my siphon incorrectly, however if I pull the bell off and manually break the siphon the siphon will (for one time only) fill up to my desired height and drain. Then the problem starts all over.

I'm stumped at what to do as I have semi mature plants in my growbed so I'd like to fix this. I really dont understand why turning the pump off for an extended period of time doesnt fully break the siphon.

Hi Charmin,

Can you post some pics?

Could it be that there is sitting water in the drain and that is what makes the
siphon so easy to reactivate?

What kind of water flow do you have?

--
Sam

Been a while since I used siphons but one thing that occurs to me is that the heavy rains could affect the pumping head height so your pump is probably pumping more water during and after the rain, than it was able to before the rain.

Siphons that work fine for awhile then play up can drive newcomers to DESPAIR hmmm I remember those days

I would dig out and check your media guard probably root mass in and around the siphon is interfering with water flow

Media guard may need more holes in it

Check your return line from siphon to sump / fish tank , it must slope down all the way (no airlocks)

You could drill a small hole in the bottom of your siphon stand pipe so bed drains during the pump off cycle

Look Look you will find the reason stop worrying about rain ect the siphon is controlled by flow rate both in and out of the growbed.