Backyard Aquaponics
A place to discuss aquaponics

I have six three inch tubes six foot long,meant to be nft,but the way I had put them together they were level and with a three inch to two adaptor at the end there was always water in the tube,so it was neither dwc or nft. So redesign,two inch adaptor rotated so there is no water holding in the tube,the run increased to 1 in 40 and the flow set at one litre per minute.
Now I am using drinking cups, forty five mm dia,that protrude into the tube about 50 mm water flowing through the tube is about four mm deep. I am starting my lettuce in sponge cubes,but to get a root system big enough to pick up in the flow I have doubled my propagation time,I have been trying air pruning to strengthen the root system but again this increases the propagation time.
The cubes are soaked in water,one seed in each then placed in a tray in a large clear plastic bag for a week,then as the first show they are put into a perorated tray,just touching pond water,this keeps them moist,then as the roots come through the sponge the level is dropped to leave a air gap,they are then watered twice a day by raising the water level to the bottom of the tray,they sit under fifty % shade cloth.
Does anyone have tips or advice to improve,change or just different to my approach.

Perhaps a rayon mop string wold work well to wick the water up until the roots can reach the water.

Put a ball valve on the supply to the tubes.... raise/drop the flood level according to root growth...

In my last attempts i have dropped the seed germination time down to two three days,I used bottled drinking water with the ph dropped to 5.5,as soon as I saw the first signs the tray was moved to to upper tray with tank water set at Ph 6,given up on air pruning for the lettuce but that does work well for other seedlings. The first attempts have slowed,but I put twenty in and they are of and running.
Now I have three inch tubes,is it an ideal to have say two,two inch tubes with the hole spacings very close,then when the seedlings show the first signs of roots,put them in the two inch with the bottom of the cup,sponge cube just on the water level,as they develop then move them on to the three inch.
This way they get well oxygenated water plus nutrients.