Decided to get off my ass and test the actual flow from my drip system today and found it was really flowing well! Too well! Exactly double the expected output … I double checked everything, didn’t find any blatant errors. So I cut the timer setting in half and got my expect output… The drippers do continue to run for 8~10s after the pump shuts off as the pressure drops but that can’t be making up the whole difference.
Thanks for the idea. This is at the top of my list to try but I can’t test it until this run ends. These drippers are supposed to operate evenly from ~12-50psi. But I think this pump runs in 45-60 range.
even if they state they should run evenly they wont because of pressure difference, its just a specific controlled sized orifice that will flow ___ volume and a set pressure, there range is more hey they will work at this range to this range but that doesn’t mean the volume is accurate which is always a ball park or determined at a pressure likely at the midpoint of their range, were not talking fine control here for drip emitter worth a couple cents
measure that 8-10sec run out till the pressure drops to stop water flow at the dripper other than that maybe possible water head pressure difference between you gauge and dripper heads where its on the north end of pressure?
@Mr.Sparkle Were you talking about a different type of dripper or can I expect even flow out of this pressure compensating style?
I’ll measure that extra water tomorrow but I’m guessing it can’t be more than 10-15mL.
Just checked the pump info again and its MAX psi is 45 (I thought that was the min/trigger), so the range is closer to 30-45.
Its all good w/ the on time being cut in half, but I’d like to understand whats happening.
Specs wise of what you posted they say it should be even flow over there pressure range, but I’d start by measuring that runout… But could be mislabeled emitters ???
I have an extensive drip system in my orchard and if I fail to completely drain it using an air compressor before winter I’ve seen drippers malfunction due to freezing damage in the internal baffles that control flow. I don’t suppose that’s your problem but thought it deserved mention in case you are running outdoors.
In re-reading the thread, I still can’t tell whether you are using a pressure regulator in your system? If you aren’t, that should be your next step. As mentioned above, excess pressure is mostly likely the culprit here.
@Mr.Sparkle I checked that, I was so confused when I collected exactly 2x what I expected. Sadly they are color coded and these are indeed 0.5gph .
Hey @GrouchyOldMan definitely not freezing in the tent! I’m putting some drippers out into the veggie garden this year so I’ll keep that in mind going into next winter .
Too much pressure is the only thing that makes sense. Hopefully everything stays buttoned together until the end of flower and I’ll test it with some pressure regulators.
I don’t know if yours have one but some emitters have a diaphragm in them to help regulate the GPH. Maybe it’s possible that a high psi could rupture the diaphragm and cause it to release more water flow?
Your pump has a pressure switch built in, you can reduce the operating pressure with an Allen wrench. But I think you are using an accumulator tank? If so, that basically will determine the overall pressure of your system, so try to reduce the pressure there by letting some of the air out.
I tried adjusting that switch to lower pressure when I was first setting this up and quickly found out you’re not really supposed to really mess w/ that allen key. I guess its set to 45psi from the factory and you can adjust it 5-10 degrees as the pump ages over the years. I had to RMA that pump lol.
I do have a accumulator tank, just checked its set at 30~35psi. When I set that up all the advice was from the RV community and it was suggested that the accumulator tank is set to ~5psi under the cut-in pressure of the seaflo (which I think is 40). This probably works great when you’re trying to shower… maybe not for growing pot… I’ll play w/ this too!
I might have been this easy! Measured 50mL of water after the pump shut-off. If you account for this 50mL extra the emitters are doing exactly as advertised, 0.5gph. Now I just have to see if that 50mL is consistent.
Ill fine tune based off actual flow and go w/ it until harvest, then I’ll play around w/ a pressure regulator to see if that makes any difference.
Sorry slow response, glad to see you figured it out.
My accumulator tank is around 25psi. I have adjusted the pressure switch downward on the pump itself too, guess I’m lucky I didn’t screw it up .
No worries man, you’ve helped me so much I’m surprised you still respond
My current mood: if it ain’t broke don’t fix it!
What I learned about that pressure switch is it’s adjusting the cut in pressure but I don’t think it lowers the max? Really not sure though.
My current plan is to place a 15-20psi regulator so the delta between the emitters closing and the line pressure is less. Thinking that will really lower my runout after the pump stops.
Just remember that the last pressurized item in your flow is the accumulator tank, so that in effect is regulating the pressure at your drippers. If you accumulator tank is set to 35psi but you are only feeding it 25psi it’s gonna mess with your flow rates, the “accumulation” part of your equation, so to speak.
Edit to say technically your pressure compensating drippers are the last pressurized thing, but you know what I mean
Hmm maybe I’ve been going about this the wrong way…
I was thinking the accumulator tank pressure bladder just helps maintain the line pressure so you don’t get pulsing if there is high flow (like a sink faucet) but the pump will still run until the switch senses 45psi, or whatever its been adjusted to, compresses the bladder in the accumulator and then it will slowly expand as pressure drops after the pump shuts off so the pressure in the line doesn’t drop too fast?
Have you checked the pressure in your lines while everything is hooked up and running? I plumbed a T in for a gauge but took it out thinking “i’ll never need to know this again…”
Geez now my old thc riddled mind is confused also. Lemme think about that.
I don’t know the exact pressure my system is operating at, but I suspect it’s around 30psi based on the pressure in my accumulator tank, but maybe that’s a bad assumption …
Every run I do recheck my drippers with a small measuring cup to confirm flow is somewhat consistent, then I just confirm my timer assumptions (I.e. a 1% shot takes 37 seconds, etc)
… I double checked everything, didn’t find any blatant errors. So I cut the timer setting in half and got my expect output… 
The drippers do continue to run for 8~10s after the pump shuts off as the pressure drops but that can’t be making up the whole difference.
. These should be regulating the pressure for me, or at least I thought so. I forgot to mention the actual model.
measure that 8-10sec run out till the pressure drops to stop water flow at the dripper other than that maybe possible water head pressure difference between you gauge and dripper heads where its on the north end of pressure?
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