Hey guys, I'm new here to the forums, but not to pools. I have read a lot of information from here and certainly appreciate those who contribute to this site.
Anyway, long story short, I have a route I take care of. Most pools along this route are well maintained and present no issue. There are a select few pools, however, that have consistent and difficult issues. Some of these pools are covered by trees, others are wide open. I will provide an example in hopes that someone can help crack the case!
Example (25k gallons): First service visit ever; moderate algae, normal for the spring time, no problem. Started up with a shock and chem balance. Next week, clear as can be. Regular maintenance includes 2.5lbs of chlorine, FC comes in fine for CYA levels, tablets are topped off (I know, I know but I can only go once per week). Everything seems fine. Let's fast forward one month; mustard algae pops up after some heavy rainstorms. I put a little over my regular amount of chlorine/acid and ask the owner to drop in about a gallon or two of liquid chlorine after I leave (they preferred that over buying extra from me since they already had it). They said it clears up next day, but within a few days later it's back in full bloom. This sounds to me like inadequate chlorination! But two to three days? Their CYA runs about 70 with direct sunlight all day. Their FC is usually maintained at about 5ppm throughout the week. I want to say, however, while this algae is present, they haven't had much chlorine in the water (maybe 1-3ppm). This is when I start adding more chlorine regularly, they add some, clears up again, but yet comes back by my next visit. They have tablets (again CYA about 70), they add chlorine sometimes, but it's still inadequately chlorinated?
This is actually one example, but the other pools are very similar. The others do not regularly use tablets however. What am I supposed to do/tell my customers? I've had one complain when I requested that they add chlorine in between visits, even though I told them that the chlorine level just needs to stay up throughout the week.
By the way, chemistry is kept up properly (except chlorine levels, they drop at the end of the week). I don't have results to post but I use the Taylor test kit, the chemistry is always good with the occasional exception to TA and CH. All filters in these examples have been cleaned after algae seemed to go away.
I'm completely against metal algaecides for wide-scale use unless there is black algae. My customers know this, and they avoid them as well. I think I will start using poly-quats. These seem to be a very subtle and preventative-minded algaecide. Aside from this, however, I only get once a week to work with, and I'm running out of ideas. Even close friends who are professionals (much more experience than me) are out of thoughts. I want to be sure that my customers are taken care of, and I'm almost tempted to simply leave them with a daily schedule since I'm starting to feel more and more useless for their pool. I just can't be there every few days like it needs. There has to be a way around this, every pool company does it.
What do you guys think? Thank you in advance.