new user, old pool, trouble with algae

[ksukris]

I've had the house/pool for 8 years, and never had a problem with the 3/4 HP pump before now. I should say I just replaced the motor, not the pump. I'm getting a test kit for high chlorine levels and some bleach today, I'll report back as soon as I can retest.

Should I be running the pump on filter or recirculate? I won't need to backwash if it's just on recirculate, right?

[aylad]

You won't need to backwash if it's on recirculate, assuming everything is plumbed and working like it should. NOrmally we would advise people to run the pump on filter while the mess is being cleaned up, and with a larger filter on a smaller pump, I'm still inclined to advise you that way. However, this year we've had a ton of folks who are having problems clearing up the dead algae once it's killed, and Pooldoc believes that sometimes it's due to forcing the dead stuff through the sand and actually having it break up into smaller pieces than the filter can catch. So....if it were my pool, I'd probably keep it in filter mode. However, if you want to leave it on recirculate until it's all dead and THEN switch back to filter to get it all out, you can do that too. Either way works, but if your filter is efficient at getting the dead stuff, then the recirculate option may just take a little longer.

Janet

[Watermom]

I am not the equipment guru around here by any means. But just wanted to share what I have on my pool since the pump size for this pool is being debated. I have a 27ft AG pool (approx. 19,300 gallons) and I have a 1/2 hp full-rated inground pump and it works just fine. I'm inclined to think that a 3/4hp on your pool should be plenty. Just my $0.02.

Welcome to the forum!

[PoolDoc]

I'm getting a test kit for high chlorine levels and some bleach today, I'll report back as soon as I can retest.

The locally available "high chlorine" tests are not what you need, 98+% of the time. Get a K2006 or K1515 (test kit page linked in my sig) online. Meanwhile, get a local OTO (see kit page) kit for now. If the Walmart's in your area have the HTH 6-way, those are an excellent value (they are a private label Taylor kit!).

[ksukris]

I ordered a FAS-DPD kit from Amazon, found out the hard way they aren't sold at the pool stores! I did get an OTO kit, but had to dilute the water substantially to get a reading. Assuming my dilutions were accurate, I'm somewhere around 35 ppm on chlorine. Running filter and keeping an eye on pressure to backwash, and brushing daily. Would it hurt to dump in a couple bottles of bleach or should I save it for when my chlorine drops? I'll test again in the morning and see if it's still around 35 ppm.

[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.