algae in pool last year late, traces showing now

[DMck]

I use a nature 2 system and developed algae late in summer last year . Upon opening pool have very clear water , balance is good but now showing signs of algae in steps and black water ring at top of steps only. I've added spot kill at a rate of 2 lbs. per 10,000 gal. and 2 days later small growth in step area and a black water ring on moulded steps again ???? Any one that can help ? ?

[dynamictiger]

The symptoms you are describing are classic for a lack of circulation in this area. The area you are describing is well known for lack of circulation.

HTH

[chrisinspring]

My concern is the black rings. Are these like the other algae, but small dot like algae that you can scrape off. You might have black algae, which is pain to deal with. If not, to deal with the algae, shock your pool, run it 24/7, add and algecide. If it's small black dots that scrape off with your fingernail than scrape off with a metal brush an shock shock and shock and use lot of elbow greese with your metal brush. Black algae is like a week that grows into your plaster. 2-3 years a we got a call from a someone that had it all over the pool, to the point it looked like a dark paster......... he needed a new plaster job.