Comment

Comment by Kobus Jooste on August 15, 2011 at 9:28am

One of those ugly Aussie acronyms - refers to a constant height of water in fish tank with a pump in sump pumping back to the fish tank, forcing the fish tank to overflow (also known as chift pist).  I have the fish tank as the lowest point, with the pump lifting the water up to the highest filter bed, from where it gravity feeds back to the fish tank.  The fish tank contains about 1800 liters, with the filter sitting at around 1400.  The fish tank can only take 2500 thus if the power konks out and too much filter water trickles back to the tank (it is usually set up just right) it can overflow.  

Comment by Carey Ma on August 15, 2011 at 9:14am

Sorry. CHOP configuration?

Comment by Kobus Jooste on August 15, 2011 at 4:51am

Mark, I thought about it, but in the end went for manual filling with a pressure pump and stop cock.  I have had a few near disasters with power failures and system balancing.  Because the filter beds are fed from the pump and I try to balance inflow with outflow, the levels in the fish tank and the filter beds can vary.  I clean the swirl filter every couple of days, and if I get the valve settings a bit wrong, the filter beds can fill up higher thqan normal.  If I was on a float, the water level drop would just activate the pump, and by the time I corrected the filter water level, I would have 100's of liters to many in the system.  If the tank is too full and the power cuts when I am not around, half of the filter bed drains into the tank and again, there are problems.  This is not a typical water flow set-up though.  If it gets reverted back to AP, I would drop the level of the gravel beds, turn the 500 liter tank into a sump and operate it in CHOP configuration. 

Comment by Mark Huppelschoten on August 15, 2011 at 3:22am

Kobus - have you used a float level pump to top up on water levels in the greenhouse?

Comment by Kobus Jooste on February 6, 2011 at 11:30am

The greenhouse was set up for a specific hybrid aquaculture research project.  We are in the middle of a bad drought, and severe water restrictions are in place.  The two tanks on the left (10 000 liters together) harvests water from the house's roof, while the smaller 2200 liter tank hidden to the right gets the greenhouse roof water.  Right now, the set-up produces bio-fertilizer.  As soon as this particular project is complete, I will try to reconfigure the system to be for aquaponics.

Comment by Izzy on February 6, 2011 at 10:46am

That is nice!  What is the tank on the left for?  How much food comes out of that (or do you expect to come out of that)?

Comment by Kobus Jooste on February 6, 2011 at 3:50am

it is a 27 square meter (3 m x 9 m) steel and polycarb unit.

Comment by Izzy on February 6, 2011 at 1:48am

nice green house, what size is that?