Backyard Aquaponics
A place to discuss aquaponics

Ok so I have been reading a lot and searching and I still have some questions I think people with experience will be able to answer easily. My system turned out to be all barrels. I have a 55 gallon sump, two 55 gallon barrels cut in half to make 4 grow beds, and will be getting the last one as a fish tank soon. I will put some pictures if I can figure out how to. Ok so my biggest issue is the bell siphon. I have read all about them and have a good idea how to build mine for the most part. However, I am not totally sure if I can get away with what I am planning. I am planning on using a 2" pvc stand pipe and a 3" "bell" portion. I figured since I am feeding four beds I need a big siphon. Oh and the siphon is in the reservior. The GBs just have a lower gravity drain and upper safety drain. Part of why I am asking here is bc I keep reading posts with pipe sizes in mm and I can't seem to figure out the conversion. Ok I will start with that issure and see if I can post some pics of what I am talking about.

An inch is 25mm ( nominally)

Here's a good chart and it's in the ANCIENT Imperial system and uses strange American gallons

http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

Cheers

Hey DavidF

here is what I use to do the conversions.....

just put in the numbers and it converts..

http://www.worldwidemetric.com/metcal.htm

jT

Just type in a sentence into Google and it can convert any units to any other units:

"9 mm in inches" ->

http://www.google.com/search?client=saf ... 8&oe=UTF-8

Download and install this handy utility... converts anything to anything ... both ways..



http://joshmadison.com/article/download ... or-windows

So my 2" stand pipe is 50mm ish.

I don't see a lot of information for that size stand pipe. Will I be ok using a 3" "bell"? Or do I need a 4"? Also how tall should the legs be on my bell portion? I forgot the term normally used for the cut outs or legs.

hey there,
did you see this link?
viewtopic.php?f=8&t=685

i have 4 u-bend syphons on mines and a weir syphon for my azolla tank. i would consider an outside bell syphon for yours though. 1 syphon to control them all! =p

Yea thats the link I have been looking at. Outside siphon??? I am planning on using one for all four. One in the res. to feed down to all the beds. The res. is the one on the stand.

oh, so how are you going to drain the growbeds?

Hellbent, like yours. I have a lower drain that goes back into the fish tank. Also a higher drain to make sure the bed never overflows. The picture from behind shows the drains with out seals yet.

DavidF I am having some trouble understanding the design you have. Are you intending to use Constant Height in Fish Tank (chift) with Pump in Sump Tank (pist)?

As I understand it you intend to have a 55g tank overflowing into a set of 4 27g grow beds, these will then drain/siphon to a 55g sump (not shown in pics).

From the pictures you seem to have elevated the fish tank quite high, the tank really only needs to be slightly higher than the growbeds to allow overflow to fill the GB's. Excessive height will decrease flow or require a more powerful pump.

The pictures don't seem to allow enough height in the GB's to place a 55g sump (unless you bury it) sufficiently below to allow a siphon to have sufficient height to function.

If you intend to use a siphon to empty the GB's you will need an external siphon (or perhaps a flout would be better) that is not shown.

Finally if you fill 4 GB's from the sump you will have 11g or less left in the sump and may run into problems with the water level for the pump. If the pump can't continue the GB's will partial flood and a siphon will never trigger. If your fish are relying on water flow for oxygen they will be in trouble.

What size are those pipes connecting the beds together? If you are planning on using a single siphon to drain all four beds, then you are going to be limited by the size of the pipe connecting the beds.

I think a 2 inch stand pipe with a 3 inch bell is not going to work. Maybe just maybe a 3/4 inch stand pipe with a 1 1/2" bell? That is just my guess looking at the pipes connecting the beds together but I can't see them very well. I only have one situation where I'm using a loop siphon with several buckets connected together. In that situation the loop is 3/4" and the pipes connecting the buckets together are 1 1/2".

What kind of pump will you be using? You siphon size needs to be somewhat based on the flow rate your pump can supply. If you build a really big siphon, and you only have a little pump, your siphon may never kick in properly and the beds will stay flooded and the water will only trickle out the siphon at the same rate that it trickles into the beds.

Also, 2 inch stand pipe and 3 inch bell might not leave enough space for water between the bell and the outside of the stand pipe to flow properly. You want about the same area that as you have going down the stand pipe. I have one bell siphon that is 3/4 inch stand pipe and 1 1/2 inch bell. for a while I had a stand pipe that was 1 1/2 inch stand pipe with three inch bell but then I converted to loop siphon.

Lol this is what I was hoping for. Ok, first things first. The barrel on the stand is the resevior. That is where my one bell siphon is going to be. I have one more barrel on the way that will hold my fish and will be located in the ground next to the resevior and behind the GB's. The pump will be with the fish in a barrel pumping up the the resevior.
The stand is going to come down more because I am burrying the legs of it for stability. It gets windy here. The pump I have is a good quality pump rated at 700gph.

I am doing CHIFT. My pump is going to be located in the fish tank barrel.
I am draining back to the fish tank from the GBs.
You can't see it well but if you look at my last picture you can see a hole behind the GBs. Thats where the fish and pump will be.

1" is actually 25.4mm however, as we used to use the imperial system, I'm reasonably sure that a 2" pipe is interchangeable with a 50mm pipe, but not certain...

The google tip is a good one, I use it all the time. google also does math for you.

2 * 5 plus 3 divided by 5 - 2 = 8.6 google uses the principal of bodmas and even brackets it for you so you can see how it was calculated, in case you can't use bodmas.

it makes it really handy when taking metric measurements, converting to volume then converting to imperial. I have NFI how imperial units relate to each other, so usually will do the following:

to workout growbed area required for a 240gal system

240 gallons in Litres
-> 240 US gallons = 908.498828 litres
-> (908.498828 / 1000) / 0.3 = 3.02832943
3.02832943 square metres in square feet
->3.02832943 (square meters) = 32.5966667 square feet

because metric makes so much more sense than that evil arbitrary system you use.