Can my pool stay home alone for 10 days?

[chem geek]

Amy,

I'd like to have more confidence in telling you how much chlorine to use and whether it will work for the 10 days. Are you leaving right away or do you have time to do an experiment? If you have time, then the following would give us enough info to figure this out.

1) We definitely need your CYA level so get that measured (do you have Ben's test kit?). This will tell us the minimum final chlorine level you can have on day 10.

2) In the evening (or any time not during the heat of the day when the sun is on the pool) test your chlorine level and add enough chlorine to raise the level to at least 5 ppm, though 10 would be even better (assuming you are using a FAS-DPD drop chlorine test kit; otherwise, 5 should probably be your starting point). Then, cover your pool. If your pump is not normally running at this time, turn it on manually until step 3.

3) After an hour, measure the chlorine level in your pool. This is your starting chlorine level. You can turn off your pump back to its normal automatic mode if its normally off at this time.

4) After 24 hours, measure the chlorine level in your pool. The ratio of this amount over the amount found in step 3 gives your retention ratio. If you want, you can continue the experiment for another 24 hours (don't add any more chlorine) since that will give you more accuracy. Three days would be even better. At the end of your experiment, you can uncover your pool during the day which will breakdown a lot of the chlorine so you'll be able to swim (if you want).

The formula for figuring out how much chlorine to add is as follows.

Starting Chlorine = (Ending Chlorine) / (Retention Ratio)^10

The "^10" means raising the Retention Ratio to the 10th power (the y^x function on the calculator).

Hopefully, the ratio of chlorine from day 2 to day 1 is about the same as the ratio from day 3 to day 2. If so, then we can be reasonably sure at our prediction. If the drop is very slow, then we can use the drop over 2 or 3 days via "Retention Ratio = ( (FC at Day N)/(FC at Day 1) )^(1/(N-1))

A simple alternative is to dump a whole lot of chlorine -- 30 ppm -- as if you were shocking the pool, but because it is kept covered, it won't really be shocked well. Your cover may not like this high chlorine level, but it will just be for 10 days (no guarantees).

Richard

[Phillbo]

another advantage of a SWG I guess.

[Watermom]

Shocking the pool and then covering it is not good for your solar cover.

[chem geek]

Shocking the pool and then covering it is not good for your solar cover.

I was afraid of that. So that means that if she feels she has to do the chlorine dump approach, then doing the experiment to determine the minimum amount of chlorine that is needed would be a wise thing to do (rather than do shock levels).

I had also thought of the possibility of temporarily switching to Tri-Chlor tabs in a floating feeder, but I don't think they will last for the 10 days and they'll be hard on the pH (though she could start at a higher pH to start).

Richard

[sevver]

How much chlorine do you usually use? Is it not possible to just tell someone to add say like a half of gallon a day til you return? Even the neighbor or something. Pay them... Everyone likes money. Get some kid, tell him that you will give him $50 if you come back to a clean pool, he has to add bleach every day, if he messes it up, no money. If it is really good tell him he gets $100.

[Phillbo]

For that money you can hire a pool service to keep it in check while your gone . probably for less than 50.00.

[poolmom06]

How much chlorine do you usually use? Is it not possible to just tell someone to add say like a half of gallon a day til you return? Even the neighbor or something. Pay them... Everyone likes money. Get some kid, tell him that you will give him $50 if you come back to a clean pool, he has to add bleach every day, if he messes it up, no money. If it is really good tell him he gets $100.

Damn, that's what I should have told my BIL!!!!

[amyinraleigh]

OK, I can't stand it anymore - WHAT IS A BIL?!?!?!

[amyinraleigh]

The only cover I have is just the cheapie whatever cover that came with the pool - it definitely isn't a solar cover (I can only wish..... ). I'm sure the thing won't last long anyway, I'm not too worried about it losing life. It's pretty thin and so I guess it probably wouldn't keep out sun anyway, I'll have to pull it out and see but I would imagine it's main purpose is keeping debris out of the pool.

I don't have the pump on a timer, I have been just turning it on whenever, making sure it's on at least 8 hours a day. I'm a bit scared of putting it on a timer because of how the skimmer is mounted - it just hooks over the inflatable ring and depending on time of day (sunlight, temp) the ring is either very taut or pretty mushy allowing the skimmer to rise out of the water. I've tried to find a happy medium on fill of the ring and tightness of the skimmer hook so as to be stable enough to keep the skimmer submerged when it's cool out, yet not too tight to do damage to the ring during the sunlight hours. I've had to adjust the hook several times after the skimmer started sucking air soon after I turned the pump on - wouldn't want this to happen while no one is there to turn the pump off and adjust things....

The pool's only been up a week and this is my "learning" pool, so I'm still going by trial and error - and of course this site!! - on most everything. CYA is still dissolving, this morning was almost 30....I think.....still getting used to the tests, Walmart 5-way, by the way, next year I'll upgrade. Can I buy a high chlorine test at a pool store? I'm not sure how I'll measure shock levels w/o one.

adding a bit of bleach to a pool daily is a very complex and intricate thing that I imagine is well beyond the grasp of some people.

I hope this wasn't meant to be sarcastic , I can't really tell.....I live way out in the sticks and it is very inconvenient for any of my friends to drive all the way out here to mess with the pool - I would never ask them to. I have many pets that are going to be graciously well cared-for by my immediate neighbors, I don't want to dump the pool on them as well. That care and time is taken with my animals is much more important to me than overwhelming the caretakers with "a very complex and intricate" additional burden - which I myself don't even fully understand.

I really am worried about coming home to a swamp, as I understand it, the shortcomings of the underpowered Intex pump really shine while trying to clear an algae outbreak , but that may be my only option. I do have time before I leave and I will try your outline Chem Geek Richard (sincere thanks for the time you put into posting your experiment! ) I'm just not sure if I'll be able to accomplish much since I'm still in the stabilizing stages and brand-new to boot. I'll try though because I might be able to bring myself to ask a neighbor to add a definite amount of a definite chemical on a definite day with no testing and adjusting responsibilities. Whether I get to know the water well enough by that time remains to be seen, here's crossing my fingers!!

Thanks for all the helpful replies!

Amy

[chem geek]

If you can leave your pump on for the filter but turn off your pool sweep (is it on a separate pump or part of the main system? -- if part of the main system can you unscrew it where it attaches in the pool?). It is most important that you get circulation and not very important that you have your pool sweep running, especially if you are using a cover which should keep out much of the debris.

Even if the cover is thin, that's OK, it's more whether you can easily see through it or not -- is it clear or is it colored. Something will be better than nothing in any event. At least it's a cheap cover so it won't be horrible if it gets destroyed through this process.

Just so you know, I'm going on vacation starting this Thursday and through the following week (yes, we have someone staying at our house to tend to our two cats and the pool) so hopefully someone else will be able to help you out with the formulas and procedure I posted while I'm away. You've got a lot of bright, experienced and helpful people on this board so I'm sure you'll do fine. Good luck!

Richard