VB,
Here is a pix of my grow bed that I planted on 3 September. My pump moves 100 ltrs of water into the grow bed in just 3 minutes via the H shaped distribution grid and I am noticing that the small 4mm holes I have drilled in the grid at approx 125mm spacings tend to clog a little with fish poo etc at the extreme end of the grid, so once a day I give it full blast (open up the ball valve) to clear them, in this case the pump out only takes about 1 1/2 minutes to move the 100 ltrs approx into the grow bed.
Sometimes it is more that 100 ltrs if the sump pump is delivering to the fish tank at the same time then the grow bed fills to a little more than 3/4 full as the fish tank float switch will take longer to switch off.
I think with a low capacity pump one would have clogging problems, eventually. The pump needs to have a bit of capacity in order to evenly distribute the water all over the grow bed via the pipe grid.
My fish water was very dirty, and when I had the float switch set to fill the grow bed right to the top the water did not clear at all. I had it like that for about one week. Upon setting the float switch to only half fill the grow bed the water started to clear overnight, so the level of flooding and distribution of the water via the grid is very important.
I have added extra seedlings one week ago, as a result of a comment of VB's I realised that I needed more plants to get the system working properly and in one weeks time I will add more lettuce, so I will soon have a regular supply.
It is amazing really, when I just copy what Joel has done it works !!!! Funny thing that !!!
Muzza
murray@aquaponics.net.au
Backyard Aquaponics
