New Pool Owner Q Black Algae & Plumbing

[gp2m]

I, am 1 month into owning a pebbletech pool built in 1990.

My current readings are FC 9, CC 0.5, TA 100, CYA 32, PH 7.2. Shocking tonight with liquid bleach.

I have had my FC as high as 50 PPM with CYA at 50...been coming down for 8 days. FC will probably be back up to 17-18ppm after tonight. I'm trying to defeat some black algae. I have been brushing with a poly brush 2-3 times a day. I don't appear to be making any progress against the algae. I am thinking of trying a steel brush.

1) Is that ok to try on pebbletech? Any other adjustments to pool chemistry?

The plumbing between the primary pump/booster pump and pressure side cleaner doesn't make sense to me. I have a total of 4 jets in the pool (6 more in spa). Two of them are dedicated to moving pool water. Two of them move a little water, maybe 25% of the other two. These are the ones that confuse me. They are tied to the pressure booster for my polaris (my polaris run on two of my 4 lines). When the pressure booster is off, some water pressure goes through the two tied to the pressure booster. When I run the pressure booster, I have to block one of the two off in order to get enough pressure to the polaris to run it.

2) Why are there two lines for the polaris?

3) Why do these two lines get some pressure from the main pump?

It seems to me that I could move more water more efficiently by have the two primary water movement jets and pressure/cleaner jet(s) on two separate pluming lines. If that were the case, it seems like I could probably use pumps half the size of what I have and move as much or more water. I've been running my primary pump 24/7 anyway.

4) Is it possible/practicable/advisable to get the two primary jets and cleaner/jet(s) on separate lines and install smaller pumps (especially on the primary pump?

Thanks!

 

[JasonLion]

Welcome to TFP!

Are you sure you have black algae? Once you have it, it is very very difficult to get rid of. Regular shocking won't do it. At a minimum you need to brush very frequently with a steel bristle brush, and usually you need to do something more drastic than that.

1) Steel bristle brushes are fine as long as it is more than one year old.
2) No idea. That is not the way it is normally done and doesn't make any sense to me.
3) Booster pumps boost the pressure from the main pump. With the booster off water from the main pump still comes through. That is completely normal.
4) Possible: yes. Advisable: probably not. Replacing a working pump almost never pays back. Replacing plumbing lines is quite expensive as it involves digging up the existing lines.