new user, old pool, trouble with algae

[PoolDoc]

Unless you have EXTREMELY high stabilizer, 35 ppm is more than enough. If your chlorine level gets too far ahead of your stabilizer level, you can begin bleaching your liner. That may happen anyhow -- liners vary widely and unpredictably in their color-fastness -- but unnecessarily high chlorine can certain accelerate it.

[ksukris]

An update: Wednesday night and Thursday morning chlorine level was holding at 35 ppm. By Thursday night, it had dropped to about 24 ppm, so I added my first dose of liquid bleach and raised it up to 32 ppm. This morning, I was reading back around the 24 ppm range, so more bleach went in. I maybe detect a small change in the water color (still cloudy light green), but can't be certain. Equipment is running fine, I've backwashed a couple times and continue to sweep. The water seems to be using the bleach faster than it was using the powder shock, does this indicate anything? Shouldn't I be seeing some results with these high chlorine levels?

[PoolDoc]

Without knowing what your stabilizer level is, it's hard to say what should be happening. If your CYA=400 . . . then, no, 35 ppm won't be enough. That's why we want a CYA test. Did you check to see if a HTH 6-way was available in your area?

I'm reluctant to tell you to go higher, lest your have LOW CYA, and bleach your liner. By the way, with OTO, 35 ppm is dark orange, without any dilution.

One quick check: are you using DISTILLED water to dilute? Most tap water has chlorine, more than enough to cause testing error, if you are diluting.

[ksukris]

CYA tested to 200 ppm. Yikes! I've been keeping shock level around 35 ppm of chlorine. Yes, I'm using distilled water to dilute, I did a quick check with full-strength pool water and got a deep orange color. As for my liner, it only has a couple years left anyway, is there any other danger to overshocking? I don't plan on jumping in anytime soon Just stocked up on more bleach, in the past 6 days I've added 16 gallons.

[PoolDoc]

With 200 ppm CYA, 35 ppm is NOT over-shocking . . . if the water is clear, feel free to swim.

(Don't tell the local health inspector -- he hasn't read the Best Guess page -- but the local country club pool I service was at CYA=100 and FC=28 most of this past weekend. Over 400 people swam, with no complaints!)

[ksukris]

After lots of reading on this forum and on poolsolutions.com, I've decided I don't want to deal with 200 ppm CYA. I've been a pool store junkie for years, and there is no telling how much crap is in my water besides the high CYA. I'm going to drain and refill. I'm aware of the issues with draining (floating pools), but that isn't a problem in my area. I lost all the water a couple years ago over the winter when there was a hole in the liner, and since the cover was on I have no idea how long it had been like that before I noticed it! No damage to the walls of the pool then, so I'd rather pay the $200 for new water from the city and start fresh. Once I have new water in, I'm going to use the dichlor I still have laying around until my CYA is 30 ppm, then switch to bleach. I'll add a little bleach as I refill to make sure I don't get an algae bloom before I can get the equipment running. Is this crazy? It doesn't sound like I have many options unless I want to deal with high CYA.

[ksukris]

Oh, and my liner only has a couple years left in it anyway. Has some wrinkles (which I know will get worse when I drain/refill), and is pretty faded. If I can get this season and next out of it, I'll be happy, then it's time to replace anyway. Water here is cheap, too. I'm really excited to get off to a good start with my new education about what my pool REALLY does and doesn't need.

[Watermom]

Sounds like you are aware of all the possible pitfalls. One thing you might try is to drain and fill at the same time using a large plastic tarp to keep the new water from mixing with the old water. That would keep the pool from every being empty. You drain from the bottom and fill from the top. It has to be a big enough piece of plastic that it can extend onto the sides of your deck so that as the volume of the water increases on top, the sheet has room to sink without falling in and allowing the new and old water to mix.

I have never done this myself, but it has been discussed on the forum before. You may do a search and read some threads. Use the search feature in my signature below.

[PoolDoc]

Oh, and my liner only has a couple years left in it anyway. Has some wrinkles (which I know will get worse when I drain/refill), and is pretty faded. If I can get this season and next out of it, I'll be happy, then it's time to replace anyway. Water here is cheap, too. I'm really excited to get off to a good start with my new education about what my pool REALLY does and doesn't need.

Your choice, of course. But I wouldn't, unless you are willing to do a liner installation in June. Old liners are notoriously brittle and susceptible to splitting.

If you really want to drain, there is a way to do a 'drain-in-place' but you'll need a tarp or pool cover that's about 10' bigger than your pool, so, for a 16x32, you'd need a 26 x 42 tarp. You could buy a new over-size winter cover, and do it with that.

Let me know if you are interested.

[BigDave]

Why not just run a high CYA pool until you replace the liner? Who knows, you might like adding chlorine only occasionally.