Backyard Aquaponics
A place to discuss aquaponics

Im building my first system. I got the siphon working perfectly before I filled the grow beds. 15 mins fill time about 5 minutes drain time. But once I put the grow medium in the beds the beds filled up much faster. So i turned down the flow of water but now the siphon will not start or takes forever to start.

Anyone have any suggestions?

Let it fill faster or until you can get the syphon to work correctly.

Where does the water go if the siphon doesn't start?

Do you have a media shield around the siphon? If not it's a fair bet your media is blocking the holes.

What kind of siphon are you using? Afnan or normal bell?

The water just flows down the stand pipe but the flow is insufficient to start a siphon. I do have a media shield but unfortunately it floats and so does my grow medium. I have to keep a brick on top of it to hold it down.

My bell has a breather tube with a little cup. I also flared the stand pipe with a heat gun.

See Charlie's solution. It doesn't really matter how fast your GB fills and empties - the guide is a minimum of turning over the FT contents once per hour. If you are doing it more often that is fine.

So turn up the water a bit...

Another issue might be the space between the top of the standpipe and the bell - if it is too high the lower rate of flow might mean there isn't enough suction to pull the water. Too low and the siphon will not break, so I would guess you might have the 1st issue.

Is there an ideal distance between the top of the stand pipe and the top of the bell?

I'm currently down to about 1" to 1"1/4. The siphon starts at a lower fill rate but it sometimes takes a couple minutes to start and stop. And its still a little faster fill rate than I was hoping for.The good thing is once the siphon starts the bed drains in less than 3 minutes which should help draw oxygen into the growth medium.

Hi Tlrobb

As an example I run a 150mm dia bell with 32mm standpipe and a 40mm short section of pipe over the 32mm standpipe at the top. (Think Affan type siphon)

The clearance is 60mm from stand pipe to bell top.

This also does not use a siphon break and is as regular as clockwork.