How dangerous is it to the pool if I empty an in-ground swimming pool temporarily?

A pool can be emptied and then refilled with little problem. The best time to empty a pool is in the summer or end of summer when the ground water is at its lowest level. Three or four days empty is normally not a problem.

The pool shell acts as a kind of 'boat' when empty of water. If the surrounding soil is saturated it will have a tendency to float, which can cause it to shift and crack. So the major factor in leaving it empty for a few days is the water table and/or soil moisture.

The longer a pool is left empty the more likely it is to have problems. But again, that depends entirely on the geology of the ground it is in. Some pools can go for years empty, then be refilled and they are still as good as new.

I supervised a commercial swimming pool for several years in Northern California where it had been constructed right on an old stream-bed. The worst possible spot to build a pool! It had a slight tilt from a previous draining which caused one end of the deck to be about a half inch higher than the opposite side. It also caused some circulation problems in the pool itself. But even with that problem, the pool was still perfectly useable and the situation manageable.

Cyanuric Acid is a buffer agent used to prevent chlorine from reacting too quickly. As you say, levels of over 100 can so completely block the chlorine reaction as to make the pool vulnerable to algae and other organisms. People need to be aware that some chlorine products bought in pool supply stores have cyanuric acid already added. Especially some of the chlorine products that comes in tablet form. One should check their cyanuric acid levels periodically and not use chlorine products that add more and more to the water. Unlike chlorine, the cyanuric acid does not go away with time, it simply builds up until it reaches unsafe levels. The only way to get rid of it is to drain the pool and start over again.

It sounds like your pool guy knows what he is doing. You should also explore the possibility of having the pool's drainage re-worked so that waste-water goes to sewage to bring it into conformity with your local building codes. If waste water is spilling into the surrounding ground, it could contribute to pool cracking even with the pool filled, and could also damage the foundations of your home or neighboring homes.

This Site Might Help You.

RE:

How dangerous is it to the pool if I empty an in-ground swimming pool temporarily?

I am having a horrible algae problem with an old in-ground swimming pool. I had the cyanuric acid tested and it was over 100 which means that no matter how much chlorine I add it will not fix the algae problem. My pool guy told me I needed to change the water. I want to pump the water out of the...

Empty Swimming Pool

Chlorine Wash Pool

My TDS(total dissolved solids) is 3500, and the Cyanuric Acid is 150, and a bad algae problem. Assuming I have to DRAIN the pool(inground plaster) and refill, right? Not up on this "scrubbing the pool" either. Why is that necessary if you put the chems in? Our pool water has been in there for 11+ years. Assuming it is time.

Your Pool man is correct. There is absolutely NO danger to your pool by draining all of the water out.. Alot of commercial/Public swimming pools that are too large to cover always drain their outdoor pool for the winter months and they sit for prolonged periods without any foundation or structural damage to the walls etc.

As for your dilemma... If you already have one, Great, if not.... what i would recommend to you is this.

your Pool guy is correct, to drain the water, and scrub it with chlorine and then do an acid wash after. that is the only TRUE way to get any contaminants off of your wall with chemicals designed for the pool industry. But before scrubbing the pool surface with a brush etc, i would rent a power/pressure washing system... You are just going to use a high powered water jet <a 45 degree angle tip.... nothing too powerful, you do not want to create any problems with your pool wall/floor by putting holes in it with too much direct forced water pressure. So that is why the 45 degree angle tip. <very similar in idea to those do it yourself car washes and the water gun you use there> So rent the power washer, and spray down the entire pool surface with the pressure washer. This will help reduce anything on the walls. After finishing this, drain out the water you've added. Now take a steel pool brush <since i assume we are talkign about a plastered Gunite pool> ans around the bottom drain <where any further water/chlorine is going to pool> start there and scrub there. You do not have to make sure the local minister can eat off the bottom of the pool. You're not trying to clean the tiled bathroom floor with a toothbrush... you just want to brush everything with a liquid chlorine, or dilute some granular shock into a bucket of water, and stir it up. <just dont use your hand... the chlorine will become warm, it wont necessarily Burn you, But your hand will smell like chlorine for a few days... > and then brush the pool. Once that is done, drain the water out and acid wash your pool. Just be sure of where you are draining the water since the water will be a highly chlorinated <or mostly chlorine at this point.... > Make sure after you acid wash the pool, that you have soda Ash available, and lots of it to neutrailize the acid.

this should fix your problem. Once you get your pool refilled, DO NOT ADD any chlorine for 2 days minimum. If you have any minerals in your water, such as Copper, Iron, manganese, you can discolor the plaster of your pool. Just add DE to your filter, and let it filter the metals out of your pool. then in 2 days or even 3, then shock your pool, and add tabs to your skimmer as yuou would normally run your pool. Since your water is also going to be fresh, you will not have any Cyanuric Acid <chlorine Stabilizer> or any other pool water chemicals in your water other than your initial dose of chlorine, It would be a good idea to take a water sample in <use a clean 20 ounce soda bottle and make sure its filled with your pool water from about an elbow length in depth> This gives the person testing the water more than enough so that if a test needs to be redone they have enough water. I can't tell you how many times ive seen people come in with a baby jar filled with water expecting a full spectrum analysis be done. It is IMPOSSIBLE to test everything with that little of water.

so because your water is new, have them test for everything, and add the chemicals as directed from your printout. Yes, it is probably going to cost you 200 or more dollars for this initial barrage of chemicals and supplies, But where you have had an algae problem before, it should be done, and done the right way, especially if you are going to these lengths to drain your pool.

Hope this helps.

Chris

We drained the pool to fis pool light. When refilling it looses about 6 inches a day. Is is possible that it has a leak.

my linger has alot of wrinkles and we have a pool guy coming to fix it, but we hated to waste chemicals when we knew it would have to be drained. It got so black you could not see anything so we drained it. How long can we leave it empty and what might happen leaving it empty. He said it would probably be a couple of weeks before he could get to it

When mine gets that way I just SHOCK it and in a few days it clears up. Most pool suppliers carry it, just need to know how many gallons your pool has to determine how much you will need. They also have a solution that helped the particles bind together to help the filter catch it after it is shocked.

If you do drain your pool you will have a lot of scrubbing to do and also have a large water bill which is why I would use the shock, but this would be up to you. I knew a guy who used a sump pump to drain his out in a field behind his house.

http://www.archchemicals.com/Fed/HTH/Products/shoc...

Shock

1