scale is rough on bare feet

[tombomb]

I have what I think is calcium deposits on floor and walls of pool. it hurts the grandkids feet like sandpaper to the point where they have to wear swim shoes. I was advised to drain the pool, give it an acid bath and refill. Is this normal for a 2yr old plaster pool. Is there another method to dissolve the calcium? Won't the calcium just come back? I use regular chlorox for chlorine and shock.
26000 gallons plaster pool, 2yrs old. filled w/well water.
fc 2
tc 2
ph 7.2 (2 gallons of acid p/week to maintain ph balance)
ta 200 (aerating to try and lower)
ch 75
cya 65

I appreciate any help and advice I could get on removing calcium.
thanks.....
tom h.

 

[JasonLion]

With CYA at 65 you want to keep FC between 5 and 10, and never below 5.

Your high TA, combined with high PH, is the cause of your calcium scaling. If you can keep TA under control, and keep everything else balanced, you won't get any further scaling.

A drain and manual acid wash is the only reliable way to remove calcium scaling. There are various other approaches you could try, but they take time and often don't work.

 

[Melt In The Sun]

How did you get those test results? My gut feeling does not believe the calcium number.

 

[blakeusa]

filled w/well water.

Well water has a lot of minerals and other metals in the water - which will compound your scaling problem. You may have to drain and acid wash, possibly buff/ wet sand to get it smooth and then get filled with city water. Its expensive 1-2K where I live, but is necessary for a plaster pool.

 

[polywise]

I seem to have the same condition in my plaster pool. Last season was our first summer with the pool, and it went well.
The rough surface seemed to have happened over the winter.

Is there any way of just using a rougher metal bristle brush to brush off the deposits v.s. draining and doing a acid wash?

 

[chem geek]

Welcome to TFP!

Yes, you can usually just lower the pH and keep it lower for a time and brush the pool. The scale should redissolve if it's relatively fresh. However, to know if this will work we really need a full set of numbers so that the Calcite Saturation Index can be calculated in The Pool Calculator. You need a proper test kit to be able to get accurate numbers -- either the TFTestkits TF-100 or the Taylor K-2006 where the former has a larger volume of the reagents you use the most so is more economical (see Test Kits Compared).