Bypass vs Demand Pump

Well, I should've looked more closely at my pumps description when I bought it. I thought it was a bypass pump, but I was WRONG!

Learned the hard way today when I came out to check out the ladies, and for the first time since starting, my heart sunk! It was bad. They probably went 12-18 hrs without water. I got drip rings in the pots being fed by one of the many cheapo sump pumps I had layin around. They'll pull through, but dammit.

I think what happened in my situation is that the 12 x 2gph misters didn't match the 198 gph output of the pump. And without bypass, it slowly wore the pump down. I would really appreciate if one of our fine HP dudes could verify that was what indeed happened. Pump was 2 months old.

Hi Mike
If it was a demand pump it would have a pressure switch onboard, if you heard it chattering a lot (aka short cycling) that would be the cause of its early demise.

It did have a pressure switch, but throught my re-circ valve I fed some of the water back into the res. Making it so that the switch never tripped. If I closed the valve completely it would short cycle, but I didn't let it.

Customer service at shurflo is A+ They're sending an 8k series pump to replace the 2088. The 8k pump has half the flow rate/amps at the same psi. He believed that was my problem, although I would think reguardless it would last more than 2 months. It never reached anywhere near it's thermal limits, and wasn't short cycling. IDK?

It should be under warranty i`d send it back. 12x 2gph nozzles wouldn`t hurt it and most pumps have thermal protection so its doubtful it could have burned out.
It`d be worth checking if the pressure switch is fubar in the open postion, that would cause it not to run.
Consider investing in an accumulator/solenoid and your new pump will last for years

It seems they're gonna send me the replacement on good faith. He didn't even ask for an order number, RMA or anything. It's kinda strange. I just went out there and plugged the pump in, gave it a good hard knock and it kicked on. Now when I run the pump with zero resistance, it sounds fine. As soon as I route the water to the misters the pump kinda chugs like a car with a dirty fuel system. Not short cycling, just running really irratically, sounding like crap. It doesn't seem to have the pressure it once did, cause the pressure switch doesn't enguage even when all power is going to the misters. I took a short vid of the sound to maybe help diagnose. Thanks!

http://www.youtube.com/watch?v=ExOFnLn5pi8

Sounds decidedly unhealthy. Its likely to be the motor windings if its breaking down under load. It could be a blessing in disguise if the replacement pump has more than 40psi, 100psi would be better.

The replacement is 60psi. I may just run the drip rings to finish out this grow. If I had only been smart & used JG fittings... Thanks for your help atomizer!

Glad to hear they'll pull through. Don't feel too bad... you're still luckier than me. I finished my large chamber a few days too late. The plants I had waiting in rubbermaid containers got too big and the roots rotted 2 days before I finished God it pisses me off. One plant was beyond hope, the others *might* come though. They're still droopy but aren't drying out. Got them in the new chamber now. I don't know if they're going to grow new roots fast enough.

You'd probably be fine with just adding a bypass to the system. I saw one at a farm and fleet a little while ago... the same one I linked to in your first thread. It was in the agricultural spraying section... $15 I think.

Mike, tried to check out your video but it'd been removed - everything is back to working correctly?

And what cycle was your pump on?

Also, maybe Atomizer or someone else would have the answer to this - if I put a 100PSI pressure regulator at the end of my plumbing, would that allow pressures less than 100PSI to pass through?

Asking because my backup pressure switch is gonna be set for like 80-95PSI or something like that...........would like to get the consistency of 100PSI at my misters every time (fluctuates from 100-125 right now), but not if it means that my backup/failsafe won't work.

Bob Smith said:

Mike, tried to check out your video but it'd been removed - everything is back to working correctly?

And what cycle was your pump on?

Also, maybe Atomizer or someone else would have the answer to this - if I put a 100PSI pressure regulator at the end of my plumbing, would that allow pressures less than 100PSI to pass through?

Asking because my backup pressure switch is gonna be set for like 80-95PSI or something like that...........would like to get the consistency of 100PSI at my misters every time (fluctuates from 100-125 right now), but not if it means that my backup/failsafe won't work.

Click to expand...

Yeah, I took the incriminating video down. The build vid is still there. Now that my girls are flowering nicely, I didn't wanna take any risks in losing them/my freedom.

I am gonna finish his grow with the drip rings. Pain to replace the pump now w/o those sweet JG fittings. I'll rebuild after this grow. Try to undo all the wrong. Plants are doing great, considering...

How are your 90 ladies doin?

They're doing okay; been working out some random kinks (like clone health, and some plants getting off to a huge headstart and being much larger than others), but all in all not too bad.

Designing my new containers now for four HP trees around that light source - will run the PVC at least one more time and maybe two, and then it gets retired to PVC Heaven (a storage locker, or maybe just the garbage).

Here's a couple of pics from a few days ago - the large plants have LP roots because I've needed to keep the small plants moist as their root system grows; now that pretty much all the plants have developed root systems, I've been increasing the pause time and decreasing the misting time.

At 3.5 seconds on / 3 seconds off right now.

Bob Smith said:

They're doing okay; been working out some random kinks (like clone health, and some plants getting off to a huge headstart and being much larger than others), but all in all not too bad.

Click to expand...

Yeah, I know about those problems.

My replacement pump came in today. I pulled the old one apart to hopefully get an idea of what happened. I didn't see anything out of the ordinary. Motor is my guess.

I had no idea how these things worked before today. The word diaphragm certainly makes sense now. Seems like such a caveman design. I imagined it much more complicated than it was.

Mike, seems I may have a similar issue to what you had - my Shurflo 150PSI pump is now running for 2 minutes at a time (used to be 30 seconds, and misting/pause schedule has not changed) every 15 minutes, and has started to sound exactly like you described - a car with an engine problem, and it's much louder than it was originally.

I could just replace with another Shurflo, but I'd prefer to spend the money and get a pump that can/will last - does anyone (Atomizer) have any good recommendations? Aquatec are supposedly quieter than Shurflo, correct? Are they more durable as well?

Thanks.

My aquatecs ran out of warranty 2yrs ago and they`re going strong. The 8800 is somewhat louder than the 6800 which is completely silent, if that helps.

Thanks; I think I'm gonna just order another Shur-Flo (only one I can find that goes up to 150PSI, which I need with my pressure switch going up to 125PSI) and see if I can figure out what happened to the first one - I could try to adjust my pressure switch, but I'm gonna pass on that.

BTW, here's an article I found for anyone who might want to try and mess around with fixing their pump:

http://www.yachtsurvey.com/repairing_diaphragm_pumps.htm

Cool article. I think my diaphragm was in great condition, and from the sounds of it yours probably was as well. The problem with mine was definately the motor. The flowrate of my pump was 4 times that of all my misters, and I ran it 15/15 min on/off. I'm not even gonna run my new pump until I can reduce the amount of work.

I just need to ramp down my misting times and increase my pauses (or, get a lot larger variation in my pressure switch differential) - pump was running for 30 seconds every 15 minutes (now two minutes and LOUD), so if I could get that down to 30 seconds every hour or a longer run (a few minutes) with a longer pause (a few hours), I'll be happy.

Howdy pump heads!! Ive got some studying to do and wondered if i could get some ideas.

Im running a low pressure aero setup i built (see pics) I finishing up the 4 walls and will be running on all 4 cylinders soon. Its low pressure (1267 submersible pump) and ezclone red sprayers.
Each wall has its own reservor , plumbing and pump. (so far so good)

The next cube i build i want it to be medium pressure and all fed by one pump and a reservoir outside the room. The pump will need to be able to feed 60 sprayers..and im hoping for at least 30-40 psi.
It will be drain to waste.

so my question is what pump would work? and also what sprayers? Ive researched the john guest fittings and tubing and i think they will work best.

Ive researched fatmans tutorial about medium pressure and a pump with a T fitting and two solenoids. I assume the pump runs nonstop with it pumping to the reservoir. And the normally closed solenoid is set to a timer that sprays like 2 seconds etc??

Any help would be appreciated.

Running a pump non-stop is wasteful on power, wears the pump for no reason and creates heat.
60 nozzles seems a lot, 24 nozzles can fill this behemoth with mist in under a second. The pump runs 15 minutes once every 5-9 hours depending on the cycle timing.