Seeking pro help for 45K gal balance act - black algae and green

[Mycall9550]

I keep adding large amounts of Acid and want to try and get ahead to keep things more balanced and stop the large swings.
My guess is with the stupid spa/fountains, it's a large amount of aeration.

The problem & case history:
Moved into home in December.
With things warmed up now I'm fighting algae. With the pitting and blistering in the plaster I don't have near the time, nor the lung power, to brush all the black algae. [edit: it's in/under the chips and blisters]
I was able to make a good dent, especially along the water/tile line, when I drained the pool to dilute CYA. I had high CYA (100) so I drained 40-50% and got it blue again... only to go on a 2 week vacation. My dad helped out and dumped 2.5 gal 10% liq chlorine for me every couple of days, but I dont think he went often enough.. and apparently we got heavy rain which dropped my CYA to 30-35.

The numbers:
Using Taylor test kit, here's the results: (pool math app)

date	FC	pH	TA	CH	CYA	CSI	Notes
6/15	0.0	8.0	150	300	35		*Pool store test to validate CYA - They use Taylor reagents and appears Pentair CYA test tube
6/14	0	7.8	120	240	20	.28
5/27	3.2	8	140	260	51	.55
5/26	5.4
5/25	6.0	7.8	140	300	35	.43
5/24	8.6	8	140	250	30	.56
5/23	15.6	8.0	140	220	35	.56
5/22	5.6	8.0	130	210	68	.46
5/18	0.0	8.0	110	200	100	.28
4/26	2.4	8.0	100	270	100	.29
4/12	1.0	8.0	105	270	90

+--------------+-------------------------------------------------------+
| DATE | notes |
+--------------+-------------------------------------------------------+
| 5/23/2017 | water test |
| 5/22/2017 | add 16# 68% cal-hypo - brush walls |
| 5/22/2017 | water test |
| 5/20/2017 | start pool fill |
| 5/19/2017 | start pool drain |
| 5/18/2017 | water test |
| manage algae | minimal bleach added to keep at bay preventing bloom |
| 4/26/2017 | water test |
+--------------+-------------------------------------------------------+



the Pool:

Drain before and after (4/26 - 5/19 era)


5/20

5/21

5/24

 

[Mycall9550]

I need to run another test, but as I mentioned(?) today I added 2 gal muriatic acid and 2.5 gal liquid chlorine.

I've been brushing the visible algae off the walls.
Water is very clear.

Just want help to see if

1) need more CYA due to full sun and heat burn off
2) keeping pH in balance (reduce swings and stay out of the 8 range)
3) figure out proper order for adding chem

 

[jblizzle]

First, that is a really cool pool!

1. In your location, I would think you should be up around 50ppm of CYA.

2. Just keep adding acid to keep the pH below 8 ... this should slowly lower the TA which should then slow down the pH rise, although the aeration is working against you.

3. Order does not really matter. Just leave a 5 minutes or so between adding the bleach and the acid.

If you are seeing algae, then you need to follow the SLAM Process process until you pass the 3 criteria to stop. That could be part of your FC loss problems as well.

 

[BattleOfYakima]

As always, jblizzle is perfect - one thought, since you might (probably) SLAM, which will have your FC above 10 and be unable to do a valid ph test again until after the slam, you might want to keep FC at 9 and do the Lower TA cycles before the SLAM.