What to do in the end?

[PoolGate]

What do you do in the end of the season when your chlorine needs are very low? Do you turn off the SWG and use bleach? I am having trouble dialing in an end of season program for very limited pool usage like 2-3 hours 1 day a week. I have been just shutting it off and then setting at 50% while swimmers are in the pool.

 

[ping]

Turn it off and switch to bleach.

 

[Teald024]

If you are still using the pool and water temp is still warm, you can do as you are and run the SWG for an hour a day at a low setting. There is no specific need for it to be while you are in the pool.
If you feel that dosing manually isn't an issue and are willing to pay & transport the bleach, you can do that too. You may find that you are still using enough bleach to warrant the SWG.

 

[Catanzaro]

I would turn off and switch to bleach. But if you still want to use the SWG, you can actually figure out what % you should dial in based on pump run time. Although, you will need to find out what your cell produces. My SWG (T9) produces 1.25 lbs. of gas per day (I have to double check the lbs. per day) at 100% over 24 hours. Then go to pool math and plug in the figures. This will tell you the total FC production in a 24 hour period. Then make the calculations.

If you can send me the specs of lbs. per gas per day and what you have figured out from pool math, I will perform the calculations and send over the information. You also have to figure out how much you are consuming daily. At the end of September I was consuming about .67 vs. 1.33 daily (without swimmer activity that is).

 

[PoolGate]

I would turn off and switch to bleach. But if you still want to use the SWG, you can actually figure out what % you should dial in based on pump run time. Although, you will need to find out what your cell produces. My SWG (T9) produces 1.25 lbs. of gas per day (I have to double check the lbs. per day) at 100% over 24 hours. Then go to pool math and plug in the figures. This will tell you the total FC production in a 24 hour period. Then make the calculations.

If you can send me the specs of lbs. per gas per day and what you have figured out from pool math, I will perform the calculations and send over the information. You also have to figure out how much you are consuming daily. At the end of September I was consuming about .67 vs. 1.33 daily (without swimmer activity that is).

Thanks I am not sure how to use the pool calc for determining runtime of the SWG. But it produces 1.25lbs/day. I have a VSP and run it 24x7 at very low RPM below 1000. So this probably will make it hard to determine runtime. I already checked and even at 600rpm the SWG flowsensor is closed and it is running. I can go in 5% increments however. No clue what I actually need I just put in my salt 1 week ago. It looks like I lose 1-2 parts per day however so as a guess I'd say I need 1 part created daily.

 

[mknauss]

Use PoolMath, Effects of Adding Chemicals. 1.25 lbs of chlorine per day is 20 oz of chlorine gas. In a 29000 gallon pool, that equate to adding 5.2 ppm of FC per day to your pool.

So to get 1 ppm FC added per day, you would set the SWCG at 20% if running 24 hours per day.

FYI -- your cell will be marginal in the summer. You may need to be ready to supplement your FC during high organic loads or bather use. The issue will be falling behind on FC during the daylight hours even though your Cell may make enough FC based on a 24 hour day.

Take care.

 

[Catanzaro]

FC PRODUCTION (4 HOURS) 0.87 4 100% LEVEL

Above is my calculations from the sheet. For 4 hours, you will produce about .87 ppm @ 100% level on your SWG, assuming you have flow. This should be sufficient for the day, but you will need to figure out based on testing. That is what I would set it at and run for at least 4 hours. You may be able to get away with 3 hours.

Keep an eye on your levels, and test each day to figure out if more pump time is the answer. Or you could switch over to straight bleach, which is probably best at this point. Add enough 8.25% to add 1 ppm daily and call it a day. Once a week make adjustments if over.

Thanks Marty for the calculation. My figures work out exactly to your calculations based on time and percentage.

 

[PoolGate]

Thank you very much! I'll have to figure out next year how to program the SWG to best continuously chlorinate the pool. With the pump running 24x7 I guess it will need to be simply a function of percent.