Device removes 1 unit of old water, replaces it with 1 equal unit of fresh water

09659

0
In The Industry
Feb 7, 2013
138
Pool Country
I'm trying to design a device that removes one unit of old water and replaces it with one equal unit of fresh water.

It must do this automatically.

I want to use it for overnight treatment of water that has too much cyanuric acid. I want to keep the water level at skimmer level at all times.

Or, is there a product already on the market that does this?

Yes, I know it will be inefficient.

Thanks
 
Technically you could just size a small line equal to your desired exchange rate and route it as a drain to the street. The your auto leveler would fill it back up or if you don't have that put a second connection on your hose bib with a small restriction orifice to fill.

Basic calcs...
 
Garden hose filling pool.

Sump pump with modified vertical float switch.

Hmm?

The issue is that the float switch would have to be very sensitive, which may not be good for the pump. It may turn on and off too frequently.
 
Then Vegas Kid's suggestion is perfect. Depending on the pool you may need to supply a temporary auto fill system, but that is simple enough. The you just make sure that the drain is slower than the fill and you are all set.
 
The simplest I can think of for relatively low volumes (a few hundred gallons per day) would involve a small continous duty submersible pump (something with a flow rate less than the minimum flow rate of your garden hose) and an improvised auto fill as mentioned above, easy to make with a cartridge type toilet fill valve and a U shaped length of PVC, plus some sort of mounting bracket to go on the side of the pool. Put the submersible pump at the opposite end of the pool from the fill hose, turn on and let the auto fill keep the pool topped off. As long as your water supply does not fail there should not be a problem. If that is a worry add a cut off float valve on the submersible pump placed a couple inches below the water level.
 

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What happens if the discharge pump gets unplugged, trips a breaker, the irrigation systems turns on and drops the pressure, etc?

It needs to adapt to changes without human intervention.

There is no sump pump to speak of. Just make sure the end of the drain line is below the water level in the pool where you're drawing the water from. As long as you a few feet of head you will only need to pull suction 1 time to get the flow going. heck you could even hook up a bicycle pump or cheap 60ml syringe to get it started flowing.

Gravity has never failed me yet...
 
Ingredient 1: High flow auto-fill connected to garden hose.

Ingredient 2: Continuously running submersible pump under water connected to suction hose with end of suction hose positioned at skimmer level.

Because the submersible pump is under water, it will stay cool even when it sucks air.

I was hoping to do at least 4,000 gallons in an 8 hour period.
 
Ingredient 1: High flow auto-fill connected to garden hose.

Ingredient 2: Continuously running submersible pump under water connected to suction hose with end of suction hose positioned at skimmer level.

Because the submersible pump is under water, it will stay cool even when it sucks air.

I was hoping to do at least 4,000 gallons in an 8 hour period.

good Lord that's a lot of water to replace. Hose is not going to do that. @ 10gpm, you'd have a huge pressure drop with a 1" dia hose.

You can drain and fill your pool every week and still come out ahead.

Not sure I understand the reason. Are you just doing this when the CYA gets high? Reactive or preventative?

You can't possibly be planning to continuously recirc 500 gph?
 
Preventative.

I wasn't planning on doing it every day. As rarely as possible.

I believe even a 1/2" garden hose can do 9 gallon/minute, and a 3/4" garden hose can do up to 23 gallon/minute.

Of course even a high flow auto-fill will restrict the flow quite a lot I imagine.

Anyone know of a good high flow auto-fill? Something that will allow 9 gallon/minute or higher?
 
Preventative.

I wasn't planning on doing it every day. As rarely as possible.

I believe even a 1/2" garden hose can do 9 gallon/minute, and a 3/4" garden hose can do up to 23 gallon/minute.

Of course even a high flow auto-fill will restrict the flow quite a lot I imagine.

Anyone know of a good high flow auto-fill? Something that will allow 9 gallon/minute or higher?

I guess it really depends on how long your run is and the inlet pressure to your hose. city is around 35-50psi. You may get away with a 3/4" or 5/8" hose.

You could also just hard pipe some PVC if you plan on doing this often.
 
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