Looking for some advise on an issue I have been trying solve.
My dosing pumps lose prime over time (about a 1 day or so) I have installed check valves on the input tube and the output tube with no luck. I have also switch the position of the dosing pumps from above the dosing containers to below the dosing containers. The last few things that I think could be the problem is the pump heads are not fully squeezing the tube or maybe there is an air leak on the tube connections but they feel pretty secure.
Do you have the ability to control the pumps in both directions? If so, an option might be to stop trying to keep prime (liquid in the line) and instead after each use of the pump you could reverse the flow so you are always starting from a known state (no liquid in the line). This way you can program your pumps to 1st go through enough revolutions to get your fertilizer to the end of your line and then 2nd you dispense a specific amount and 3rd you run the pump in reverse to put the fertilizer back into the their storage tank. I do this because I don't want the chance of any extra fertilizer getting into my reservoir.
i have the same problem , mine never stop losing liquid , and i need to remove the bottles to not overfet my plants
I will try to run in reverse and remove all the liquid from the line
if some one interested in see the rror i have made a video
Do you have the ability to control the pumps in both directions? If so, an option might be to stop trying to keep prime (liquid in the line) and instead after each use of the pump you could reverse the flow so you are always starting from a known state (no liquid in the line). This way you can program your pumps to 1st go through enough revolutions to get your fertilizer to the end of your line and then 2nd you dispense a specific amount and 3rd you run the pump in reverse to put the fertilizer back into the their storage tank. I do this because I don't want the chance of any extra fertilizer getting into my reservoir.
Nice looking setup you got there!
thanks @sshscp , I would have to add more pump controllers to control the direction, I am using one L298 driver for 4 pumps so I only have done direction. I do like your idea though, I am not too worried about extra nutes in the res but more worried about dosing a/b at the same amounts. I can live with it being a few mls off now that I have an EC meter I dose until I get to the desired EC and not just go by the recommend feed schedule ml's.
@avanni my pumps lose prime over the course of a day or so and once the lines are empty nothing more drips into the res. Your setup seems like its siphoning which I see how that can be a big issue.
I was surprised that the check valves did not fix the issue, I think the only other way is to have the pumps and nutes both below the res water line but that may be a little tricky
with pumps above liquid also use a one way liquid check valve to maintain the intake flow you require and it doesnt take much effort for the pump to create draw every time its activated
