Net cups filled with old coir. Rs.10 tap filter on outlet and inlet.
Filters are excellent. In 2 hours of operation nozzles never clogged. But outlet filters clogged with coir residue resulting in water accumulation in tower. Inlet clogged with dust causing pump inlet of soft pvc to pinch.
Switching 30s on-off reduces problem substantially. But inevitably it will clog.
So coir is out and clayballs will have to be substituted.
@TechNife suggested gravity based trapping (say contained overflow pots) help reduce clogging ?
The towers already have a head of 25mm. I was hoping it would precipitate particles. It does not. Probably the falling water causes sufficient turbulence.
@TechNife I feel some centrifugal + gravity based jugaads incorporated into the flow should yield the most interesting affordable automagic reductions in clogging the filters on the main flow paths. Trials & errors I guess continues.
@vvcstemplay " I also suspect a centrifugal input will considerably reduce the problem. Very cheap faucet extensions have nice little plastic fans in them, moulded on a metal pin. Inserting one in the inlet will set up a nice vortex, that should throw the lightweight coir fragments away from the nozzle."
I was about to test the above suggestions including purchasing some filters from Amazon. But lazy me cooked up a new hightech filter. A HoleeGram Filter
A bottle punctured with holes and a sock.
Pipe is fitted in a hole in the cap.
The ensuing conversation on telegram
@TechNife , [08.12.20 19:10]
[In reply to VicKram Crishna]
@TechNife, [08.12.20 19:10]
@vvcstemplay , Is it this 
?
@vvcstemplay [08.12.20 19:52]
[In reply to TechNife]
Yes, I also use one like this in the taps. It prevents water splash, by diffusing the flow.
@vvcstemplay , [08.12.20 19:57]
Of course, the coir particles won’t be removed. So, at some point, you’ll either have to redesign the entire tank system so that the excessively particle filled water is led into a wastewater settling tank, or start using either throwaway or washable filters.
The trouble with a simple settling tank is that the pump evidently causes too much turbulence, and the particles don’t settle under their own weight, or else are less dense and will never settle. If the latter, you can’t use a settling tank at all, and must think about a filtration system.
JT D, [08.12.20 20:45]
[In reply to VicKram Crishna]
Dual tank system. Ideally with a recirculating filter pump. The problem is the higher cost.
However the sock holeegram filter is working well. I removed the outlet filters, so all the debris falls straight into the tank. The much larger surface area spreads the particle trapping and the lower speed stops sucking the larger bits which settles down or floats. Tomorrow i will make 4 more for the outlets. I simply punctured holes with a solder iron. Which catches the sock, making removal a irritant. Tomorrow will drill proper deburred holes. So changing socks becomes simple. Even so not very scalable.
JT D, [08.12.20 20:52]
Changing the bottle and sock together is extremely easy. Just unscrew the cap and screw on a second. If it can function without cleaning for several days, it would drastically reduce routine cleaning.
Three hours of nonstop running without problems. Tomorrow I will make 5 proper HoleeGram Filters with deburred holes and fix 4 on the outflow pipes and one on the inflow of the pump.
@Pneb will also add the electronic control to turn on/off the pump and some level control and alarms.
The PSU used is a PC SMPS used to power Intel Atom motherboards. It is a 400W psu and the 12v section can deliver 20A, well in excess of the 6A required when both motors on the pump is running.
. Yes. Unfortunately water level and rs485 link are likely to mess up a 555, though we could implement a 556 level control.
. But seriously a fully discrete transistor implementation would be fun.
.