How does rain affect a pool

TamithaSue50

Well-known member
Jun 6, 2018
184
Parkersburg, WV
Kinda new to the pool scene......dealing with a cloudy pool but have only been using test strips which I have learned here are no good so I'm hoping to get a good test kit soon but I was just curious how rain affects a pool. We have been having alot of rain this last week and like I said my pool is already cloudy and I don't know what my "real" readings are so at this point it's not an urgent question but thought I would ask any.......for future reference. If it's not good do people cover up their pools when they're not using them or does that really matter?

Thanks,

Tamitha
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
20,474
Northern NJ
Water runoff from rain into your pool can bring algae and other organics that your pool sanitizing system needs to kill. Otherwise it can grow into a petri dish of stuff.

Rain can affect the PH of your pool. Which way depends on the PH or your pool and your rain water.

Rain can dilute the chemicals in your pool. How much depends on the size of your pool versus the amount or rain and runoff into your pool.

We can help you better with your questions if you put the details of your pool in your signature.
 

TamithaSue50

Well-known member
Jun 6, 2018
184
Parkersburg, WV
Well I don't know all the details about it because it's my b/f's pool......but it's a 15X42 above ground pool with vinyl siding and he has taken off the filter that came with it and put a sand filter on it....but not sure what kind it is.
 

sambot

Active member
Jun 1, 2018
35
WV
Hi Tamitha, I just wanted to say hi to a fellow West Virginian! I'm from Wheeling - and we've certainly been getting lots of rain!

I bought the test kit they suggested and it helps so much with getting the chemistry right in your pool.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,209
Central California
Rain that is running off something into your pool, depending on what it is running off of, can adversely affect your pool's chemistry, clarity and sanitation, depending on what the runoff is dragging into the pool with it. For an above ground pool, that usually doesn't occur. Maybe some water off a surrounding deck, but that's usually not a big deal, and would only occur if the deck wasn't built to drain away from the pool, as it should.

Rain water that just falls into a pool doesn't do much, unless it is so much rain that it causes the pool to overflow. If rain just falls in a pool, it can affect pH a little, but not much else. The added water will eventually evaporate, and the pool will be back where it started, chemically speaking. If the rain's pH is different than the pool's, then, yes, the pH might be affected, but not my much and it would be easily corrected with some dosing of simple chemicals.

If there is so much rain that the pool overflows, then the additional rain water will dilute the pool water, and all the chemical balances would likely be affected to some degree. So you'd test all the levels, and adjust each as needed. If you use the TFP method of testing and dosing, "fixing" a pool after a rain is a simple thing.

Now if we're talking about a big storm, that blows leaves and other debris into the pool, that's another matter. (But still correctable with the right know-how and some effort.)
 

Leebo

Admin
TFP Expert
LifeTime Supporter
Jul 21, 2011
10,078
Eastern Ohio
Keep going just a bit north of Wheeling and you’ll hit where we’re at. The rains the last week really didn’t do much to our pool.

If the water is cloudy I’d really suspect algae is starting to form. If I were to bet, there’s a SLAM in your future.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,209
Central California
All day rains yesterday took my pools PH from 7.4 to 7.8. Luckily my pool deck is slightly slipped away from the pool so not much runoff water can get in.
Yep, that's how they're supposed to be built. I think it's even a code requirement. Though I'm not sure if that's typically considered for an AGP. Wood decking would drain naturally, and unless it was built to overhang the pool frame, there would not be any runoff into the pool at all.
 

TamithaSue50

Well-known member
Jun 6, 2018
184
Parkersburg, WV
Rain that is running off something into your pool, depending on what it is running off of, can adversely affect your pool's chemistry, clarity and sanitation, depending on what the runoff is dragging into the pool with it. For an above ground pool, that usually doesn't occur. Maybe some water off a surrounding deck, but that's usually not a big deal, and would only occur if the deck wasn't built to drain away from the pool, as it should.

Rain water that just falls into a pool doesn't do much, unless it is so much rain that it causes the pool to overflow. If rain just falls in a pool, it can affect pH a little, but not much else. The added water will eventually evaporate, and the pool will be back where it started, chemically speaking. If the rain's pH is different than the pool's, then, yes, the pH might be affected, but not my much and it would be easily corrected with some dosing of simple chemicals.

If there is so much rain that the pool overflows, then the additional rain water will dilute the pool water, and all the chemical balances would likely be affected to some degree. So you'd test all the levels, and adjust each as needed. If you use the TFP method of testing and dosing, "fixing" a pool after a rain is a simple thing.

Now if we're talking about a big storm, that blows leaves and other debris into the pool, that's another matter. (But still correctable with the right know-how and some effort.)
*****I ordered my test kit today.....should be here Tuesday, I hope. The rain doesn't run off of anything it just rains directly into the pool but there are a couple trees around so there is alot of leaves and other debris that get in my pool. I try to clean it out every day but sometimes especially since I don't have my test kit yet I let it go and clean it every couple days......I figure those leaves and etc will be a real pain in my butt. If there is some that blow in the pool every day will that cause problems and if so how soon......in other words when I get my test kit and get everything the way it is supposed to be will I need to clean all leaves and other debris out every day?*********
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,209
Central California
*****I ordered my test kit today.....should be here Tuesday, I hope. The rain doesn't run off of anything it just rains directly into the pool but there are a couple trees around so there is alot of leaves and other debris that get in my pool. I try to clean it out every day but sometimes especially since I don't have my test kit yet I let it go and clean it every couple days......I figure those leaves and etc will be a real pain in my butt. If there is some that blow in the pool every day will that cause problems and if so how soon......in other words when I get my test kit and get everything the way it is supposed to be will I need to clean all leaves and other debris out every day?*********
Yes, the leaves are a whoooole 'nother matter. They are organic material, so your chlorine will go to work on them, and that will lower your FC level, which could leave your pool susceptible to algae, and other nasties getting a foothold in your water. That's just the leaves. They'll have other material attached to them (dust, dirt, bugs, bird poop, etc) that will compound the problem, use up even more FC, and affect your clarity (both organic and inorganic material floating around in your water).

So the less time leaves and other blown in debris spend in your pool the better. Don't wait for your kit. Net 'em out. Use a leaf rake to get them off the bottom. Keep your skimmer basket clear. Keep an eye on your pump basket and keep that clear, too. And monitor your filter pressure level, which let's you know when it's time to clean that out.