Backyard Aquaponics
A place to discuss aquaponics

Greetings

Got a new system and I have tried 3 different siphons.
Bell, and bell siphon 2.0 and the U siphon with (2) 45 elbows and (2) 90's
Sometimes they fired, most time they don't

(Pictures later)
my aquaponics system is in my basement, because my back yard is so shady I can't grow a garden

My pump runs water to my ibc tank which flows into my growbed. it trickles down into my GB slowly.
The water gets near the top of my U siphon and starts draining without siphoning.The rate coming in is now at the same rate as leaving the GB and siphon wont fire. I am using Harbor freight 265 gal pump

It appears I need a higher flow rate coming in?

1) faster pump?
2) Does constant flow do well ?
3) or the drain and fill work best?

How many gallons is your FT? How high above your pump is your FT? I am guessing your pump is losing quite a bit of flow rate due to height. Can you measure your flow rate?

Constant flow does do well according to previous research. I think if you can reduce your head on your pump, it will flow faster or else you may need a faster pump.

+1

Most pumps have a graph or table that tells you the volume of water pumped at any given head height. The head height is the height difference between the top of the water the pump is in to the highest height you are pumping to. I didn't see one for this pump but you might want to look around and see if there is one.


1) If you want to get the siphon to work, you'll probably need to up-size the pump. If you don't care whether you're using the siphon and want to just run it using Constant Flood then you might not need a new pump. Is all the flow going to the grow bed or is some being diverted back the the fish tank for aeration?

2) I'd call this Constant Flood since the grow bed is flooded as well as having constant flow and yes it does work. Normally you'd completely remove the bell siphon and if you have a weep hole in the standpipe that would also be removed and replaced with a standpipe that doesn't have a weep hole. Using Constant Flood the water remains in the grow bed if you have a power outage and the sump or fish tank water level is fairly constant. Constant Flood is easier to expand because you don't have to resize components to account for the additional water as much.

3) Not much difference really - Have a look at the BYAP Trials thread where they compared 3 different types of systems - http://www.backyardaquaponics.com/forum/viewtopic.php?f=1&t=8621

I've had my bell siphon running bullet-proof for over a year now. Basically I just restrict the drain a little bit and the siphon sets and runs great. I use 3/4" PVC for the center drain pipe and I neck it down to 1/2" PVC under the grow bed. I even added a venturi to the 1/2" section to add some oxygen to the water. The restriction helps create the siphon by slowing down the flow of water being drained away from the top of the siphon area, and it sets up great every time. If you need a higher drain rate, just increase size ie. 1" drain w/ 3/4" neck.

Cheers!

I have a 55 gallon barrel below with the sump pump (Aprox 260 gph) pushing up about 4' to top of fishtank

I don't think the pump is actually near the 260 gph rate but if constant flow is doing well for people than no worries about the siphon.

Thanks for this information guys
can't wait to get to growing Veggies again
Hope it works well I got about $200 invested in this system.

since you specifically highlighted "constant flow" in post above and it was mis-cited in the original post that referred to it...

"constant flow" - is technically incorrect in the context of the quote above. A siphon for example does operate in a constant flow scenario (constant flow simply means that the pump is on 24/7 or for extended periods and water is being constantly delivered to the grow bed).

in grow bed terms there is either constant flood or flood & drain.

the correct term is constant flood - because it means that the media is not being drained.
ie. the grow beds stay full of water all the time = constantly flooded (so constant flood).
if you remove a siphon then you have constant flood because the watre level now stays the same.

the alternative is flood&drain because as the name suggests there is some level of filling and draining.
the method used to achieve this (timer or siphons) is immaterial. Ebb&flow means the same thing - just tends to make something sound more complicated than it actually is.

thanks for the correction
Constant flood


IF constant flood works well then that is what I shall go with

all good.

note the main issue with constant flood is that you can get preferential flow paths develop and crud can build up in dead or low flow zones. Leading to oxygen issues (anaerobic zones).
Flood&drain forces the water to refresh because once empty new water has to flow back in to the pore spaces (gaps between media).

It is often handy to have the ability to manually flush out a constant flood grow bed - usually either by simply removing the standpipe or else by putting a ball valve / tap at the bottom of the grow bed to enable it to be drained. Can do this once a week etc.

usually you don't want this flush water going to your fish tank - so have some way to get it to a bucket and put it on pot plants / fruit trees etc.

Oh but I aint growin any pot plants at this time.


sorry couldn't resist

>> Oh but I aint growin any pot plants at this time

Ha ha .... but I suspect they could be better off in the AP anyway....

guess the fruit trees is the only option left... or some other plants that may have been glossed over in the redirection of the first lot of text Funny thing about the English language.....

You could increase the input or you could decrease the output. Have you tried just blocking the drain hole a bit at time?

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No I haven't
I think I will go with a CF system

Use narrower tubing in your u syphon.