Friday, December 18, 2009

Another system

As you can see the plant growth in the second system is quite luxurious at the moment. This is our salad vegetables plot and at the moment we are clearly not eating enough bushes. The fish are eating very actively and I have to restrict their food intake as the GB is not really big enough for 175 fish which are up to 80mm long.

I have now finally got the third system up and running. This is supposed to be the large fish purging system but we have still not caught any of the eating size fish. I have cycled the tank, with nitrogen rich water from the black tank system, and it is now stable with a low or nil ammonia level.
This was the original planned second system but the bits didn't arrive in time and so I built the black system shown on previous posts and in the first pic of this post..

This new system has another variation on the fill and drain mechanism. I am using a bell syphon to drain the grow bed instead of the float switch and/or timer mechanisms of the previous systems.
I decided to try bell syphons because I have had problems with the other systems as I have outlined earlier.
A bell syphon is a simple device which basically allows filling to a pre set level and then an almost complete empty of the grow bed back to the fish tank. The pumps run continuously. The full flood/drain cycle takes about 14 minutes.
I tried using a single 6 watt pump but it can't fill the GB fast enough to trigger the syphon so I am running 2 of the little pumps. I bought them very cheaply on eBay some time ago and have been looking for a use ever since. The top of the bell syphon is visible in the last pic.
This growbed is being used as a part herb garden and part seedling production area. Di has already planted out the pumpkins which sprouted in the gravel.
It is really easy to start seedlings in the aquaponics gravel. Just scrape a bit of a trench and sprinkle in a few seeds and wait. Provided the weather is warm enough you get plants within a week or so. MUCH easier than the seedling mix which has to be kept moist and the beds covered etc with the old fashioned way. And no need to transplant if the initial seeding was done in a sort of even way.

2 comments:

gemmell said...

Bell Siphons are the bomb. My 1st system used them - I was so blown away by how it was all driven by simple physics, flood, drain, flood, drain, no electricity required.

I find the standpipes are much less fidlly to get working though.

Jim said...

Interesting how we try all sorts of different ways to get these systems to work. My current setup (#3b) has another bell syphon and it simply worked first time- and every time after.
The big original system needs constant top ups and can't really be not checked every day. These little ones are much easier to run.