withaknife420
Member
How do you like posts? Sitting here trying to figure out how lol
Thanks for the help folks
much appreciated
Thanks for the help folks
much appreciated
Pump impeller vanes keep breaking
- Thread starter withaknife420
- Start date
rkymtnman
Well-Known Member
don't think new members can like yet??How do you like posts? Sitting here trying to figure out how lol
Thanks for the help folks
withaknife420
Member
None at all, also water fully changed weekly with 90 litres RO water. Never seen any sediment at all, very clean system.
rkymtnman
Well-Known Member
if you have access to Danners, check out their spec sheets and try to figure out what one you need. or call them and tell them what you are doing with a spray bar system.
Failmore
Well-Known Member
Guess it depends on how long and how often you run it. Plastic pumps are what they are. Plastic. Does seem like a short life tho. But I assume you run your pump a lot harder than mine.
J232
Well-Known Member
I ran mine with no filter, only issue was spilling hydron in the system and being to lazy to catch it all, I ran a 1” suction line and had to cut it to get the balls out. Most organic matter and whatnot won’t bother the mag drive in my experiences.
rkymtnman
Well-Known Member
that's why i used shower drains instead of bulkheads. that extra metal grate keeps all the big shite out of the drains
J232
Well-Known Member
I took the hydro out for now, I would do something like that if I was to redo it. Even just a plate on the drains before the res.
Drop That Sound
Well-Known Member
I've been using EcoPlus brand pumps for a long time with great results. The fixed flow versions are submersible or inline, and come in whatever size you need.
I got a 1267?+ GPH one for the LPA\NFT dual rail system that I'm building right now (I have to pump up a few extra feet from the res so need a bit more power). There's 16 sprayer nozzles for each rail so 32 total.
So.. I'm gonna try experimenting with a one way check valve\solenoid, to keep the spray bar manifolds mostly filled up between ON/OFF cycles. That way the pump doesn't have to force out all the air (that will get sucked back in through the sprayers every time it shuts off). Keep it primed at all times, especially in my situation of having the rails higher than normal on a loft. Just thinking ahead to when I get it set up because I can see that being a problem with the air. Maybe yours too? Mag drives weren't designed to cycle/pump air and water.. especially every 4-5 minutes, even if the air is only in the output line side. The way I see it.. unless you have the water level of the res exactly at the height of the sprayers in the container, you will always have priming issues working against the pump.
Also, cavitation might be what causes the impellers to crack. Heats it up or something? Not sure really. Some materials can react to the solution for sure and shouldn't be used. Also leech toxic particles. Maybe they have to use weaker plastics that are approved. I'm gonna take a wild guess though and say they make the plastic fin section cheap on purpose. As if the whole serviceable mag drive pump concept was designed just so they could sell extra parts all the time. You should be getting more than a year out of one...
I can say the 396 are probably the best all around pump that I know of. Sometimes they go on sale @ amazon for like $22-24 and I usually pick up a few extra when they do. They work good for so many different kinds of smaller systems, and I've only ever broke the included oddly size threaded fittings themselves by being too forceful.
They also have more expensive premium "mag drive" versions (w/ replaceable impellers), but I have yet to get one because the standard sealed up (mag drive as well) pumps seem to last forever, and work great for me.
I got a 1267?+ GPH one for the LPA\NFT dual rail system that I'm building right now (I have to pump up a few extra feet from the res so need a bit more power). There's 16 sprayer nozzles for each rail so 32 total.
So.. I'm gonna try experimenting with a one way check valve\solenoid, to keep the spray bar manifolds mostly filled up between ON/OFF cycles. That way the pump doesn't have to force out all the air (that will get sucked back in through the sprayers every time it shuts off). Keep it primed at all times, especially in my situation of having the rails higher than normal on a loft. Just thinking ahead to when I get it set up because I can see that being a problem with the air. Maybe yours too? Mag drives weren't designed to cycle/pump air and water.. especially every 4-5 minutes, even if the air is only in the output line side. The way I see it.. unless you have the water level of the res exactly at the height of the sprayers in the container, you will always have priming issues working against the pump.
Also, cavitation might be what causes the impellers to crack. Heats it up or something? Not sure really. Some materials can react to the solution for sure and shouldn't be used. Also leech toxic particles. Maybe they have to use weaker plastics that are approved. I'm gonna take a wild guess though and say they make the plastic fin section cheap on purpose. As if the whole serviceable mag drive pump concept was designed just so they could sell extra parts all the time. You should be getting more than a year out of one...
I can say the 396 are probably the best all around pump that I know of. Sometimes they go on sale @ amazon for like $22-24 and I usually pick up a few extra when they do. They work good for so many different kinds of smaller systems, and I've only ever broke the included oddly size threaded fittings themselves by being too forceful.
They also have more expensive premium "mag drive" versions (w/ replaceable impellers), but I have yet to get one because the standard sealed up (mag drive as well) pumps seem to last forever, and work great for me.
TintEastwood
Well-Known Member
Do others run their pumps at this frequency/interval with success?
Little plastic impeller vanes probably stress/flex at startup. Flex too often, fail.
withaknife420
Member
This was my initial thought as well, infact I think that's the main issue, you can hear the air a bit at the beginning of each cycle, especially after a harvest and cleaning, where the system is emptied fully (including the sprayer rails). I ran a check valve in a super old setup of mine (one of my first) but noticed it had an "initial pressure" the valve needed to reach before it would open up, and it caused reduced flow so I removed it. But I may retry this as my setup/pumps are much more adequate now, and maybe try to find a check valve that has a weak spring.
From the reset/cleaning today from my last crop & warrantied the pump again, I went on a search to find the broken vanes. What a bitch. Had to disconnect each section of tubing to make sure they were clear, but the rails themselves are cemented so couldn't take them apart. Heard them rattle inside, had to remove each sprayer on that rail and use a vacuum and shaking it to convince them you come out.
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withaknife420
Member
As far as the grow quality, I'm very impressed.
If I leave it too long on this aeroponics setup, the plants tell me they're thirsty. Especially during flowering. Not sure what others are running at, but I heard 5 mins is a safe value. Could probably go longer though.
Treesomewanted77
Well-Known Member
That’s what I was thinking or maybe the on off if there is some pressure in the line maybe back pressure when it shuts off it’s breaking the veins but all just a guess
Treesomewanted77
Well-Known Member
Try a check valve just off the pump may eliminate the air in system and will keep from any back pressure
Drop That Sound
Well-Known Member
I'm thinking one of the flapper/swing type check valves would work best. What do you guys think? I would have mine placed vertically right after the pump.
I might have to pickup one of the clear PVC ones, so I can see it operating. The double union ones look nice. Maybe even tweak the little spring, if there is one. Gravity alone would be enough to close the valve..
Like this:
https://www.pvcfittingsonline.com/valves/pvc-swing-check-valves/clear-pvc-swing-check-valve.html?size_in_inches=38
I might have to pickup one of the clear PVC ones, so I can see it operating. The double union ones look nice. Maybe even tweak the little spring, if there is one. Gravity alone would be enough to close the valve..
Like this:
https://www.pvcfittingsonline.com/valves/pvc-swing-check-valves/clear-pvc-swing-check-valve.html?size_in_inches=38
withaknife420
Member
I settled on a 1/2" PVC valve, was $8, that normally uses a spring, but I removed the spring to get more flow. Works great, still stops backflow, although there was a reduced flow but not by much, way better than with the spring. Can be installed in any direction since the weight of the water alone closes the valve. Going to try a 3/4" tomorrow with reducers, to see if I can restore the lost flow.
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withaknife420
Member
I thought air would be easier to pump too but my thought is that the air comes out in sections of the rail, not all at once, causing the pump to speed up/slow down until it's stabilized with water only, perhaps once it hits the water only stage that the speed at which the pump was moving suddenly meets resistance, breaking off the vanes as the pump is still moving fast at that exact moment. There is a good 3-4 feet of tubing filled with air plus the sprayer rails as well.
PH always regulated between 5.8-6.2.
But yes I agree it could be a cheap pump but I'm hearing others are not having this problem either. Most pumps I've found use the plastic impellers, except earlier mentioned in this thread was the Danner pumps that apparently use rubber.
The current flow with the 1/2 valve seems to be reaching the net pots which is good enough for me to try it at least, will see if the 3/4 restores what I lost in pressure.
If I don't have success there I'll look up the more expensive pumps. Impellers are cheap though it's just the hassle of finding the vanes stuck in the sprayer rails afterwards, which can't be done mid grow because the roots have settled in place making removal of the sprayers impossible. I've also been looking into moving to high pressure aero instead of low pressure, removing the need for sprayer rails altogether, and using a pressure tank to deliver the spray with Teffen nozzles.