GPH to PSI converter? Hydrologic stealth RO pressure problem.

AnselAdams

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Will a 950gph mag drive pondmaster pump create enough pressure to run a Hydrologic Stealth RO 100?
I own the same RO unit and i'm on my second. I love this unit.

You don't need a pump to run this. Just hook it up to your outside water faucet. I run my with the faucet open about quarter to half open into a 35 gallon holding tank that i keep a small air stone running. I am on city water and my output ppm is about 3-4pp with new filters.

If you are not using household pressures, then the question is how far are you looking to push the water? The longer the distance, the more pump you need. Twenty feet can be done with the smallest pondmaster 250 without over pressuring the membranes. 🍻
 
I had a little giant hooked straight to the system. Gave me around 15psi. Tested the clean "RO" water and it was @ 115 ppm, same ppm with the waste water. Do I need to hit a higher psi for the membrane to seperate particles properly?
I also replaced the lower sediment and carbon filter.
Would the upper membrane cause this from being clogged?
20200325_130618.jpg
 

AnselAdams

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I had a little giant hooked straight to the system. Gave me around 15psi. Tested the clean "RO" water and it was @ 115 ppm, same ppm with the waste water. Do I need to hit a higher psi for the membrane to seperate particles properly?
I also replaced the lower sediment and carbon filter.
Would the upper membrane cause this from being clogged? View attachment 954097
Looks like you have about a 13-15 gallon rez. I use a 750 on my 40 gallon rez with a chiller 15 hose feet from the rez and have no problems maintaining 63-65F. How many tubs are you going to run?

To answer your original question, i suspect you are running too much pressure. Try slowing the water being delivered to the filter. The filter is only rated at 12GPH so don't expect a flood, it really is like watching paint dry. I would suggest slowing way down and check your output ppm again. If it is still the same, return the filter (i had to do this once, replacement came in two days, via amazon).

p.s. there is going to be a high pitched whine/sucking sound if you connect an airline to that venturi inlet so be prepared to put a piece of foam over the end as a sound and dust filter. It is a nice feature as it adds micro-bubbles to the rez as well without the noise of an air pump.

Suggestion. Put that pump on a UPS so that if you lose power it will keep running and supply water movement AND air to keep your rez alive. A power outage can mean death in a very short period of time.

Happy Growing 🍻 🥂
 
How many psi is a typical garden hose? hooked it straight up to that and still nothing. I need to produce 32 gallons of RO water every 10 days. I'm going to slow down the pressure and see if that lowers ppm. I'll report back with results.

I never thought of the power going out...any good links for a backup UPS?
 
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How many psi is a typical garden hose? hooked it straight up to that and still nothing. I need to produce 32 gallons of RO water every 10 days. I'm going to slow down the pressure and see if that lowers ppm. I'll report back with results.

I never thought of the power going out...any good links for a backup UPS?
My well pump cuts out at about 42psi and city water I think is in the 55psi range.
 

AnselAdams

Premium Member
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My well pump cuts out at about 42psi and city water I think is in the 55psi range.
How many psi is a typical garden hose? hooked it straight up to that and still nothing. I need to produce 32 gallons of RO water every 10 days. I'm going to slow down the pressure and see if that lowers ppm. I'll report back with results.

I never thought of the power going out...any good links for a backup UPS?
These are the ones i use. I have 5 of them for different reasons. Summers are a beating with their "brown-outs".
https://www.amazon.com/CyberPower-CP1500AVRLCD-Intelligent-Outlets-Mini-Tower/dp/B000FBK3QK/ref=sr_1_3?dchild=1&keywords=ups&qid=1585271941&sr=8-3

Good Luck & Happy Growing 🥂 🍻
 
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AnselAdams

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My well pump cuts out at about 42psi and city water I think is in the 55psi range.

You might still give it a shot before you buy a pump. If it does not work then you might only need something like a 250-500gph. Keep in mind, that no matter what pump you buy, the suggested processing output flow for that unit is 12 gallons per hour. If you want to use a high volume pump, make sure you put a valve of some sort in-line so that you can shut the flow down to the recommended input pressure range (check their website for that model). A cheap valve will save the membrane of your expensive high quality RO filter.

Cheers!! 🍻
 
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I think you either have a intercoursed up RO system or it's not hooked up right. It should give you low ppm at just about any pressure. My well water pumps thru it fine, just not much water without a pump on it. Is the membrane installed correctly?
I may mention I have a different RO system but the principles are the same for any RO system.
 
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AnselAdams

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I think you either have a intercoursed up RO system or it's not hooked up right. It should give you low ppm at just about any pressure. My well water pumps thru it fine, just not much water without a pump on it. Is the membrane installed correctly?
Are you past the return date? It may just be defective. membrane put in backwards, etc..... just a though.
 
You might still give it a shot before you buy a pump. If it does not work then you might only need something like a 250-500gph. Keep in mind, that no matter what pump you buy, the suggested processing output flow for that unit is 12 gallons per hour. If you want to use a high volume pump, make sure you put a valve of some sort in-line so that you can shut the flow down to the recommended input pressure range (check their website for that model). A cheap valve will save the membrane of your expensive high quality RO filter.

Cheers!! 🍻
I just need.to find the time to set it up again. I have a valve for the little giant to slow down the pressure. I would love to dial in the RO for the general hydro waterfarm. I have a feeling it might be the membrane
 
I think you either have a intercoursed up RO system or it's not hooked up right. It should give you low ppm at just about any pressure. My well water pumps thru it fine, just not much water without a pump on it. Is the membrane installed correctly?
I may mention I have a different RO system but the principles are the same for any RO system.
I fully agree, even at a high pressure it should still read psi. Colour coded so it's pretty straight forward. The new pressure gauge is a bigger thred size so that will have to wait. Here's some pics of unit
 
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Not sure why you'd want to slow it down. I have a pump designed for an RO system and the output pressure to the membrane is 85psi.
 
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I fully agree, even at a high pressure it should still read psi. Colour coded so it's pretty straight forward. The new pressure gauge is a bigger thred size so that will have to wait. Here's some pics of unit
Double check your 4way valve plumbing. They are easy to hook up incorrectly.
 

AnselAdams

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Not sure why you'd want to slow it down. I have a pump designed for an RO system and the output pressure to the membrane is 85psi.
I was not sure what the rated pressure was. So then we start looking at other possibilities. I agree with whomever suggested verifying the plumbing of the filter.
 
GPH and PSI are like horsepower and torque. Flow rate is not indicative of pressure. No way is that submersible pump going to supply enough pressure to feed that system adequately. I believe optimal for the hydrologic is 40-60 PSI. If the problem is low pressure, consider a demand/delivery pump.
 
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To answer your original question, there isn't such a thing as gph to psi. Take a pond pump for instance if you have a 40gph pump that has a lift of 10 feet and the 1000 gph pump that lifts 2 feet, the 40 gph will have more pressure than the 1000gph pump. Does that make sense? You have 3 pumps, if you want to use the one with the most pressure, use the one which has the highest lift, that's the one with the most pressure.
 
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GPH and PSI are like horsepower and torque. Flow rate is not indicative of pressure. No way is that submersible pump going to supply enough pressure to feed that system adequately. I believe optimal for the hydrologic is 40-60 PSI. If the problem is low pressure, consider a demand/delivery pump.
You beat me to it. And agree that a pond pump won't give give him the pressure he's looking for.
 
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After you make sure everything is correct. Hook that puppy up to your garden hose wide open. You should get a ppm in the 3-13 ppm range. The only thing that will happen at a lower pressure is you will have more waste water. The higher the pressure at the membrane the less waste water you'll have. But it will work if it's not defective.
 
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