Help! 911 - algae showing up

[sw_stupid]

I got my kit and everything has gone well for about a week. This weekend, I noticed my ph looked to be about 8.0. I added some acid to bring it down. I think I added too much (1.5 gallons). Anyway, pH now seems to be back up to about 7.2 or 7.4. I have noticed I have some green algae trying to grow on the walls as well as a little cloudy water. The algae seems to be under the jets - maybe coincidental. Is it possible the pH change let some sort of algae start??? Here are my results:
FC = 6
CC = 0
pH = 7.4
ALK = 120
CAL = 120
CYA = 55
Salt = 3600
My initial thought was to shock (with bleach of course), but I have no CC and my FC is high enough for my CYA levels. I wouldn't freak out, but my wife is having her office party over here next weekend (July 1). I threw in a jug of bleach tonight for good measure - should bring it up to around 8.
Any suggestions?

[duraleigh]

I'd shock it. Cl up to around 17ppm in a vinyl pool...higher if your pool is plaster. Unusual that you have no CC's but seeing the algae would be good enough for me.

[sw_stupid]

What about the pH bouncing around? You think it contributed?

[duraleigh]

No. If I had to guess, I would surely guess there was a lack of Cl at some point that allowed it to start.

[sw_stupid]

I'll start shocking tomorrow. How low would you recommend it before I let the kids back in? Thanks again.

Dave to the rescue!!!

[Simmons99]

When the clorine is below 10ppm and the PH is within normal range.

[sw_stupid]

Okay, lost here. I started shocking. Checked it at lunch today using OTO test (in Ben's kit). It went dark yellow with one drop of reagent. So by the time I got the fifth drop in, it was YELLOW. So I diluted it with 4 parts tap water (checked it - no chlorine). Gonna multiply my result by five. Result barely changed from clear. So I did it again with 3 parts tap water. Exact same color. I don't want to have to use all my powder testing all day while I shock. So is there anyway to limit the number of drops it takes to perform the test? Example: put it one drop and then multiply result by five? Just a thought 'cause I'm at a loss here. Pool is still cloudy with no CC. (this is very depressing, just when I thought I was gettin it - guess the pool wanted to remind me how ignorant I am.)

[duraleigh]

You cannot test high Cl levels accurately with that OTO test. You need to get the FAS/DPD test out of your kit and use it. There is no other satisfactory way. The OTO is for testing levels of 5 or less and the dilution method is an inaccurate stop gap, at best. Also, if you are dosing accurately, you have no need to test more than once each day...simply testing for consumption...not to see if you put in enough Cl.

[let_her_flicker]

While you are shocking your pool, you need to brush your vinyl walls. Also, since you have an SWG the PH is always going to drift up. You will eventually be able to figure out a dosing strategy to keep the PH within operating parameters.

I would check the SWG thread to see if anyone talks about adding a small amount of muratic acid on a daily basis versus a lot at one time.

You may also have to make adjustments to your system to produce enough chlorine to keep FC between around 5 to 10 ppm constantly to keep algae from taking hold again based on your CYA level.

Good luck and brush those walls.

[mbar]

You can swim while shocking your pool. It won't do any damage to anyone - just wear old bathing suits, because they may fade a little.