Backyard Aquaponics
A place to discuss aquaponics

Hello All,

I'm new to the forum and Aquaponics, I've got a pretty simple set-up about ready to start. It is a 15 gallon tank beneath a grow bed with an auto-siphon. The auto-siphon is working pretty well, though I do think I may need to add a snorkel to make it more reliable at stopping. My problem is that my pump is on it's lowest setting, yet is still filling up my grow bed about every five minutes. Is there a way to slow it down? I don't really need it to flood and drain more than once an hour do I?

thanks for any insight you might have.

Hi Geo, Welcome!

Well designed and built siphons don't need breather tubes to operate reliably. Essentially it comes down to water flow into the GB... the water flow must be "tuned" to get the siphon working. Too slow and the siphon won't initiate, too fast and the siphon will initiate easily, but not cut-off when the GB is drained. Every siphon has an "operating window".

So in saying that, it's the diameter of the standpipe in your bell siphon that determines the flow rate through you GB every hour. The larger the diameter of your standpipe, the more flow required to get the siphon operating, so more water through your GB every hour.

There is no such thing as an ideal number of Flood & Drain cycles per hour, rather you should focus on getting your FT water volume (or as close to it as possible) turned over through your GB at least once per hour once per hour.

Here is a recent thread with a list of design and operating criteria that help make a siphon work reliably: viewtopic.php?p=515474#p515474

Cheers!

Hi Gio,

Add a bypass that leads back to the tank/sump, so make 2 lines, 1 runs to the beds, and 1 runs back to the tank. that will serve as your aerator other than the return.

+1 kidmmafia - just send excess back to tank as aeration

Use a ball valve tap to allow flexibility and vary flow rate

(ball valve can actually be at beginning or end of GB delivery pipe - either works)

[quote="kidmmafia"]Add a bypass that leads back to the tank/sump, so make 2 lines, /quote]

and you can put that second line to practical use by the use of a filter system..
eg. Swirl Filter, and a bio filter..

ie.. why not make the most of that water flow..

suggestion of the solids filter will reduce some of the need for Bio-Filter cleaning..
..
.

..
and, the alternative is using a tap to reduce the flow..

Doing that could increase the power required to move the smaller volume of water, and could reduce the life of the pump.
..
.

Good point of clarification Buidoi..... and important to avoid confusion

I had actually meant to use the bypass method of 'kidmmafia' and use the ball valve to balance the flow between GB and return to FT but reading it now maybe that is not too clear.....

I did what kid mafia did. I felt that using an oversized pump will allow me to expand my system without the need of a second pump.

+1 " send excess back to tank as aeration"

how ever I would also add an "venturi" for even more aeration

but yeh I would not restrict the pump as it will use more power but redirecting excess is quite possible with 2x taps

Come on all you nay sayers here they are telling him to send it back to the tank isent that chop 2 that's bad isn't it

Yea, CHOP2 = sending chopped fish poo back to the FT, don't do it.

Use a standpipe and a timer, so the pump doesn't run all the time.

Alternatively, and contrary to popular, and oft repeated, opinion, restricting the flow in many pumps does not increase the power use, it decreases it. If you don't believe me, look at the published power vs flow charts for your pump- power use is usually lower at lower flow rates.

I'd run the over sized pump up to an intermediate tank, with a level sensor to switch the pump on / off as needed to keep it full. Then siphon water from the intermediate tank to the grow beds that is sized appropriate to the needs of the grow beds.


Brian H.
Uxbridge Ont Canada

how about adding a dimmer switch?

A normal motor uses more power under.increased load..

But. One thing is do hold strongly, is the belief that increased load from restricted flow afffects the permanent magnet in the impeller, weakening it and eventually, it does not want.to spin...?
...

As far as the pump is concerned, I'm pretty sure there is no difference between putting a tap on the end to restrict the flow, and moving the end of an open pipe higher to produce a higher head. In both cases pump is moving less water.

How is "restricted flow" any different to pumping to a higher head, from the viewpoint of the PM?