Drain And Clean

[rocks]

I have an older pool, maybe 12 years old, I bought the house as a foreclosure so I dont really know, but I was wanting to drain and clean the pool. I've been in my house for 3 years now and have learned a lot about pools in that time. I now understand about CYA or cyanuric acid and what elevated levels can mean to trying to keep the pool algae free and because my CYA levels are way high I'm gonna drain and clean the pool. I had a nightmare of a summer last year trying to keep the algae out of my pool because in addition to the CYA issue I also had pool water leaking by my backwash valve so my ability to properly filter the pool water was diminished.

I dont really want to do an acid wash because the plaster is old and pitted and I cant afford to have the pool replastered right now so what would be recommended to clean the plaster and be sure to kill any algae?

[chem geek]

If you get the CYA level down to reasonable levels by diluting the water (i.e. partial drain/refill), then you can maintain a shock level of chlorine where the FC level is around 40% of the CYA level and keep it there for a while which, along with brushing, should kill algae on the plaster and remove any organic stains.

[Rocks911]

Thanks for the reply.

I did exactly that last year and didnt have great results. While my CYA levels did go down I was left with a ring around my pool down to the level that I drained it. It's kinda hard to axplain what the ring is because I cant get it to go away. It's not algae, at least not green which is what is the most common in my pool but rather it's kinda dark, not quite black but some kinda staining probably in the piited areas of my plaster.

After the partial drain and refill I expected the surface of the pool that was exposed to the air to be fairly pristine but it actually took on the stained appearance. I have no idea what to think. I thought that the air/light exposure would have killed everything but instead I have more of a problem in that area.

So I want to drain the pool completely and clean it so there is no viable algae or other organism, so again, whats the best way to clean the plaster that is not too destructive? I saw something posetd about boric acid, is that right? What should I use that will kill everything, maybe whiten some of the staining and not be too destructive to the plaster?

[chem geek]

I'm really sorry that happened to you. This is the first time I've heard about any sort of partial drain/refill leaving such a mark -- this is done all the time by pool service people to dilute the water (they can also use continuous drain/refill, but that wastes more water). A full drain can be dangereous for an in-ground plaster pool if the water table is high as the shell can crack or pop out of the ground. That's why multiple partial drain/refill or continuous drain/refill are recommended instead. Also, people in areas where they winterize their pools lower the water level below the skimmer (and returns) without incident. Perhaps others can chime in with their opinion of what you can do.

[AFiremanFirst]

I believe your dark ring to be oil, ie body oils and such, sun tan lotion etc. I like a product called oile eater! I add it to the pool and leave it running for 3 hours, then I turn the system off. It's a good idea to plug your over flow drain if you have one, and overfill your pool to get maximum effectiveness. After the system has been off for 12-18 hours, you'll notice a cloud lingering in the bottom of your pool! Vaccuum this out and clean your filter. If this ring is oil... There is a strong possibility that acid, nor chlorine will remove the junk!

Now, about your stains... and pits... Is it possible your pits are not pits, but valleys between hills. Think of it this way. Calcium and minerals sometimes build up over time and create "plateaus" between these plateaus is your original plaster! Leading you to believe that your pool plaster actually has pits when in reality your plaster is covered by buildup. The likely hood that your pool was so neglected for so long, and now you have pits, would be rare!!! I'm not saying it hasn't, but plaster is dissolved with low TA, low pH and low CH. That combination is rare for long periods of time!

If draining is your decision, I don't have a problem with draining (so long as you know your water table height, ie, nearby lake or pond level in relation to your pool, and so long as you are not in the bottom of your neighbor hood (the low spot)), then drain it with a rented sump pump to your sewer clean out in the front yard, I like to cut my back wash line and attach my sump pump here! using a flower watering pot mix your acid 50/50 to water and add a tablespoon of dish soap. The soap helps keep the solution on the wall a little longer than straight solution. rinse using a pressure washer (gently, but a garden hose is often not enough). You'll also want to have a wet vac handy as you won't be able to completely drain your pool, vac the excess up, place your sump pump in a large bucket and dump your vac stuff in the bucket for the pump to deal with. It's a process, but well worth it IMHO.

[Rocks911]

AFiremanFirst,

Thanks for the reply, most helpful for sure. Oil might just make sense, never thought of that. The buildup you mention also makes sense as I cleaned the surface thoroughly 3 years ago and dont remember it being as pited as it seems to be, or rather relatively pited from buildup.

Thanks for the process explanation very helpful. Also insofar as the water table and/or being situated at a low spot these are not really considerations that effect my situation as I'm high up on a hill just one lot down from the top.

Thanks so much for responding.

[AFiremanFirst]

It sounds like you're going to drain and clean, so allow me to elaborate!!! It is unlikely that you will remove all of your build up, if it is as bad as I invision. Don't panic! And don't over wash with acid or get too carried away with your pressure washer. If you do... You will likely remove enough plaster in areas to expose your shotcrete, yuk! Insted!!! Drain the pool, pressure wash what will come off (ie algae) and then do your first acid wash, I like to work in small areas, maybe 4-6 ft at a time top to bottom. I strongly encourage you to wear a canister mask!!! You should notice a change in color as you remove the first layer of build up, multiple washing are sometimes necessary, but be very very careful that you don't wash your plaster all the way down! When you get back to the color of your plaster, stop washing, even if you still believe there is build-up. When you refill the pool, it will likely have a low calcium level, and some of your build-up will return to the water as the water will leach it off to balance its self.

I also forgot to mention that a leaf rake (surface skimming net) on top of your bucket, for when you are pouring your vaccuum contents into the bucket to pump out is a good trick for catching the stuff that will clog your sump pump! Also! I like to wear rain gear with acid washing. The gas turns back into acid when it contacts water, ie sweat, ouch!!! That pretty much covers the basics. when you have all of the junk out of the pool, run fresh water into your bucket to clean up your pump!

I think you will be incredibly suprised at the results of your labor! Good luck

[Rocks911]

Thanks for the reply.

What type canister mask?

I know respirators can get expensive, so what is the cheapest mask that will work?

[Rocks911]

I was also looking for a recommendation for a pool light. Mine is pretty shot, I rehabbed it last year but it leaked again so I'm think of replacing it when I do the drain and clean. I was thinking about a colored LCD. I want it to be simple and reliable, thats pretty much it. Any recommendations?

[AFiremanFirst]

We're talking about a chemical that when you inhale, it turns to acid in your lungs! Go with the most expensive mask you can afford! Lights. Did you replace the seal when you replaced the bulb? Think about LED like this! If you use your light often, then it will pay for itself. If you don't its an investment you may never really see the benefit of! As far as simple, most are all internally controlled by flipping your switch! In other words, it's plug and play! I'm not a fan of Hayward lights! Outside of that, most will do!

[PoolGuyNJ]

When replacing a light fixture, use the same brand so it fits the niche and maintains UL certification. I have found that people that update to the LED fixtures tend to use the lights more than they did before.

If you have a Hayward Astro Light, get a Color Logics 4.0 fixture. If you have an American Products (now Pentair), get an IntelliBrite fixture. Etc...

Scott