Thinking about setting up a reservoir of chlorine lower than the eyeball so it won't run out when the pump isn't running......and just connecting the chlorine line to the port in the eyeball for aeration (that I never use). The suction from the water flow should pull chlorine from the reservoir and would just need to be metered. It would probably need a check valve to keep water from filling the chlorine tank when the pump shuts off. Am I missing something??? Anyone tried this method?
Auto chlorination using the suction (aeration) port on the Intex eyeball?
- Thread starter JAndyD
- Start date
- May 23, 2015
- 24,581
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
TFP’s hydraulics expert, @mas985 , has done something similar to your proposal -
www.troublefreepool.com
Homemade Acid OR Chlorine Injection System
Having a plaster pool with a SWG and fill water with high PH and TA has meant a constant battle with rising PH. I have tried the borax route with lowered TA but because of the high TA fill water, I haven't had much success in lowering my acid use. So I decided to look into acid injection...
www.troublefreepool.com
I don't believe the Intex aeration eye will work properly due to the density differences with air and bleach. It may be difficult to get a suction hose hooked up as well. You could try it and see if it works.
I looked into this idea using a eductor/venturi (same principle). There are chemical eductors out there that do just what you are suggesting. One I found when looking was by Mazzei but there are others. It involves adding a bypass loop around a valve to create a pressure differential. The eductor needs a non-trivial pressure differential to work. Then you need to size the eductor to match your specific flow and pressure created by the pump. Then see what the suction flow would be. The amount of flow and pressure through the eductor sets the suction flow capabilities for the bleach. You would then meter the bleach by running the pump at the appropriate amount of time or you can use a valve on the suction line to adjust flow. It is a viable solution if you can find the right eductor for your plumbing system and bleach flow needs. But it does need to be tuned properly.
I decided that I preferred to have a Stenner system instead. I could run the main pool pump filter as I wanted and not have bleach additions tied to pump run time or pump flow. Then I could use a simple timer to turn the Stenner on and off and pump known amounts of bleach into the syatem based on Stenner run time. I also didn't need to engineer a solution to size the eductor.
Edit to add: Mas985's system uses the suction side pressure of the main pool pump to suck fluid out of a reservoir. This fluid is then put directly into the pump basket at the drain plug. Not my favorite location to inject acid into a system.
I looked into this idea using a eductor/venturi (same principle). There are chemical eductors out there that do just what you are suggesting. One I found when looking was by Mazzei but there are others. It involves adding a bypass loop around a valve to create a pressure differential. The eductor needs a non-trivial pressure differential to work. Then you need to size the eductor to match your specific flow and pressure created by the pump. Then see what the suction flow would be. The amount of flow and pressure through the eductor sets the suction flow capabilities for the bleach. You would then meter the bleach by running the pump at the appropriate amount of time or you can use a valve on the suction line to adjust flow. It is a viable solution if you can find the right eductor for your plumbing system and bleach flow needs. But it does need to be tuned properly.
I decided that I preferred to have a Stenner system instead. I could run the main pool pump filter as I wanted and not have bleach additions tied to pump run time or pump flow. Then I could use a simple timer to turn the Stenner on and off and pump known amounts of bleach into the syatem based on Stenner run time. I also didn't need to engineer a solution to size the eductor.
Edit to add: Mas985's system uses the suction side pressure of the main pool pump to suck fluid out of a reservoir. This fluid is then put directly into the pump basket at the drain plug. Not my favorite location to inject acid into a system.
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I did a quick mock-up using an aquarium check valve and control valve I had laying around. I didn’t time it, and it wasn’t drawing a long distance, but with the valve wide open it sucked 16 oz of bleach out of the cup in about five minutes or less..... seems doable. When I shut off the pump the check valve kept it from filling the cup with water from the pool.
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Was this mock-up using the aerator of the Intex eyeball? Do you have the model number of this? It would be interesting to see some pictures of how you had it setup.
How would you plan on controlling the bleach dosage?
Yes I made a new cap for the aerator port and hooked it up with aquarium hose. I haven’t experimented with how much I can slow down the draw of the system, but it appears the valve will allow me to control the flow. It will just be a case of figuring out a baseline of how much I want to add each day and then get the flow paced to match
That intex thing that screws into the return (the little cartridge muffler thing) IS a check valve BTW.
It's probably NOT chlorine friendly. Looks to be a foam rubber type deal.
You can regulate the dose by dilution as well, figure out how much liquid is drawn in your pump run time and then dilute the bleach to match.
I've been thinking of doing the same thing so I'm glad it's working as I expected to. The intex system is a proper venturi setup so there's a significant pressure differential there.
Is it possible to draw liquid from the ground?
It's probably NOT chlorine friendly. Looks to be a foam rubber type deal.
You can regulate the dose by dilution as well, figure out how much liquid is drawn in your pump run time and then dilute the bleach to match.
I've been thinking of doing the same thing so I'm glad it's working as I expected to. The intex system is a proper venturi setup so there's a significant pressure differential there.
Is it possible to draw liquid from the ground?
I haven’t tried pulling from a tank on the ground yet, but that is the plan when I get some new hose today.
Yeah I saw there was a built in check valve in that aeration port. I assumed it would be made somewhat chlorine resistant since that outer chamber probably fills up with water when the pump shuts off. I went ahead and added another check valve to have a little insurance. Dilution was my plan if I am not able to slow down the flow enough to get the correct amount of chlorine in 4 or 6 hours of runtime.
Yeah I saw there was a built in check valve in that aeration port. I assumed it would be made somewhat chlorine resistant since that outer chamber probably fills up with water when the pump shuts off. I went ahead and added another check valve to have a little insurance. Dilution was my plan if I am not able to slow down the flow enough to get the correct amount of chlorine in 4 or 6 hours of runtime.
I wonder if it's self priming from the ground level?
Edit: I modified one of my intex returns with a piece of conduit to make more of a nozzle (it's a 3/4 to 1/2 inch adapter) that clicked into the tabs on the backside of the eyeball, which should reduce the pressure differential and thus suction. If you're having trouble slowing the flow enough that might be an option also. You'll have to fill the holes around the eyeball with epoxy to achieve the desired effect.
I'll take a picture later if you want.
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My guess is it will pull from ground level, but only time will tell...... maybe it will slow it down a little to make it easier to set the required rate. I would be curious to see how you modified yours, think will have to open mine up to figure out what you are describing.
Just got a longer piece of tubing to reach the ground, and I have started a test to see how long it takes to drain a gallon jug of water. I didn’t have to open the valve much to get it to draw, so now it is just a case of getting the chlorine delivery calibrated.
When it gets really hot.....how soon would you start to see degrading of the chlorine from being stored in the heat/sun?....anyone? It will be easy enough to shade the jug/tank, but it will still be hot.
When it gets really hot.....how soon would you start to see degrading of the chlorine from being stored in the heat/sun?....anyone? It will be easy enough to shade the jug/tank, but it will still be hot.
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Ok I thought it was drawing, but it isn’t. Looks like sitting on the ground may not work, but I am trying to draw through a very small tube. May try some of the plastic tubing they use for ice makers it is slightly larger bore tubing than the aquarium tubing.
If you are pulling it right from the gallon jug, then you’ll be fine for the couple of days it’ll take to use it.
Tubing size isn’t your issue. Bleach has a higher specific gravity as well. The differential pressure across the educator isn’t great enough to create the head you need.
It appears the valve is my problem. It is a very used (and cheap) aquarium valve, and it was sucking air from around the knob and cutting my suction to the point it couldn't draw from the longer tube. Couldn't get it to work even placing the jug up higher....it was sucking too much air around the threaded shaft of the valve. I'll find a little ball valve or something better quality and try again.
It had enough suction to pull the liquid up to the valve, but the air leak was using up too much suction to get it to flow through the valve.
It had enough suction to pull the liquid up to the valve, but the air leak was using up too much suction to get it to flow through the valve.
The aquarium tubing may be collapsing under the pressure as well. You may need to use poly-flex tubing to keep it open under suction.
I didn't see any signs of that being an issue, but I will keep it in mind. It creates steady suction , but it doesn't appear to be that strong.
Just realized I could test my theory about the valve with what I have. I just took the valve out of the system and went straight from the check valve to jug and it is pulling water out of the jug now. I tried it with bleach as well, and it is working too.
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I'm a machinist, so I made it on a lathe out of some UHMW plastic I had laying around.
After about and 1.5 hours it had sucked about 3/4 of the gallon of water (approx. it's dark outside so it was hard to see) so it looks completely doable to dilute the chlorine to the right strength to deliver the needed amount during the pumps run time. If it was diluted correctly, a control valve really wouldn't be needed.....just a plastic tube and a check valve and the new cap.....and a tank to hold the chlorine solution.
After about and 1.5 hours it had sucked about 3/4 of the gallon of water (approx. it's dark outside so it was hard to see) so it looks completely doable to dilute the chlorine to the right strength to deliver the needed amount during the pumps run time. If it was diluted correctly, a control valve really wouldn't be needed.....just a plastic tube and a check valve and the new cap.....and a tank to hold the chlorine solution.
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