Massive algae issues

Hi all,

I have severe algae issues. I have relied on my local pool store and I've neglected it over the winter, and as a result, the algae is out of control. I decided to go the Cl2 bleach method of shocking the pool because I'm tired of getting hijacked at the pool place.

I purchaced a taylor 2600 test kit which came in on the 28th, and I've been adding 2gal of 6% bleach every evening at 830pm for a week. The 27th was the first day since I started adding the bleach that I was able to carry a free Cl2 residual all day.

The test kit came in on the 28th. and here are the readings I've taken so far:

4/28 8:00pm (before nightly bleach addition): CYA90ppm, Free.4ppm, Combined CL.8ppm
4/28 10:00pm (2hrs after CL2 addition): free15ppm, combined CL1.0ppm
4/29 6:00pm (before CL2): cya80ppm, free 3ppm, combined CL2 .8ppm, alkalinity 60ppm, PH 7.6
4/29 12:30pm (2hrs after CL2) free 15ppm, Combined CL2 1.5ppm

Pool specs: 12000gal 24' round
Pump/filter: Hayward 50gpm sand filter, 40gpm pump

Am I doing this properly? I'd like to avoid draining my pool if I can.

PS: I fully deserve any ridicule I get for letting my pool get in this condition, so please heap it on.

With a CYA of 90ppm you need to taret 20ppm FC for shocking. From 0-20 that would be almost 4 gallons of 6% if you've really got 12k gallons. I say that because after adding 2 gallons you hit 15 which doesn't work out quite right in 12k gallons of water. According to the pool calculator, 2 gallons of 6% would add 15ppm to 8200 gallons.. or maybe the bleach you used was a little stronger than the label said. Try dosing 3 gallons and see where you get, remember your target should be 20ppm to shock based on the Best Guess chart. Do that until you can go from sundown to sunup without losing more than 1ppm.

Thanks for the reply. The bleach I used was some that I picked up on sale at the local grocery store. It was value time bleach, I think. I just picked up some walmart brand stuff today.

I need to make a couple of corrections to the original post:

The test kit is a Taylor 2006A and my filter is a 25gmp sand filter.

Thanks again!

Quick update:

I added the bleach as you suggested and finally got to 21.5ppm last night, lost 5ppm by morning and added 9qts of bleach. I took a sample at 1:45 today and got 20.5ppm, so I added 6qts. It looks like I'm starting to get ahead of it. Thanks again!



I have a little more clarity on the pump/filter. The filter is a Hayward s144t sand filter with a filtration rate of 25gpm at 50psi which holds one 50# bag of sand. The pump is a 1hp 40gpm hayward. Sorry for the lack of info. The stickers on the filter canister came off and i had to do alot of digging to get the right info.

After doing a bit of reading on the forum, I think I'm greatly over-pumped and under filtered. I went to the hardware store today and picked up a ball valve and installed it on the pump discharge. Under normal conditions the filter usually runs at 12psi, so I throttled it back to 6psi after I backwashed. Hopefully that will help the filtration, as I currently have only about 8" of visibility. If this doesn't help, I'm gonna try some D.E.

Looks like you've done the homework--congratulations!!

You're doing it all right--just stay the course and let us know how it's going. :)

Shure will, thanks.

I may have found a replacement filter, a 300# Hayward S244S for $200 localy. Would this be overkill for my pump?

No, it will work well, BUT you'll need to be careful in your plumbing so that you can deliver 40 - 50 gpm to the filter during backwash. If you can do that, you should get excellent performance from that filter.

If you can send pictures of your pool & piping layout (send to poolforum@gmail.com) AND tell us the model of pump you have, we can probably make some suggestions.

Hi Ben,

The pump is a hayward s48e48a04, 40gpm 1hp. I can't take a pic of my setup at the moment, but I replaced the pump discharge hose with sched. 40 1 1/2" pvc piping. My drain hose is also 1 1/2".

That's the AO Smith motor number; possibly on a Hayward Power Flo or Power Flo LX. You need to look on the plastic part of the pump, where the pipes connect, for a label with an SP number, like SP1540C

Oops, its a SP1540CFP.

Yeah, it should be OK. I can't find the electrical characteristics on that pump.

You probably need to put a valve between the pump, to throttle flow back some, to keep the motor from overloading. The filter will have so little 'back-pressure' with that pump, that you may create an 'over-flow' situation, which results in overloading the pump.

Do all the piping with 1.5" pipe, and add a 1.5 ball valve between the pump and the filter. You'll need to throttle it a bit during normal operation, but open it wide when backwashing. You should be able to get really, really clear water with that combo.