I'm seeking the forum's advice on my supervisor's behalf ...
Her 24x52 AGP was installed in May 2009. They live in a new subdivision ... less than 5 years ago it was a tillable crop field. Within a month after the pool was up & running, lots of sprigs of nutgrass started growing through the liner. Turns out the installer used some of the backhoed dirt along with the sand in the bottom. Because of that, they forced the installer to come back out, remove that liner, redo the sand, put pramatol down & then install a new liner (25 gauge).
When outside last night, she noticed 1 or 2 sprigs growing through again. Needless to say, she's stressed completely out & doesn't think the original installer will do anything again a year later. She called a local PB who told her he would remove the liner, use another chemical that he says will kill anything that's growing/will grow, & install another liner. His liner cost (not including install) is $1200 & told her that liners purchased online are not of the same quality as his. He also said he recommended putting down some type of hardbottom pan & doesn't recommend a gorilla pad. By the time they pay him for his materials & labor, it will probably be $2000 plus.
My main question for the experts here ... is he feeding her a bunch of bs about "his liner" being better quality than what she can purchase online? Wouldn't his 25-gauge be the same as any other 25-gauge? He also said there are some liners treated with herbicide but that $1200 was not for that type of liner.
Also, any other advice about killing/preventing this aggressive nutgrass growth is very much appreciated.
By the way, we also used the same installers & process of using pramatol with our pool build in July 2009 (same 25 gauge liner as well). I just watched them very carefully to make sure they didn't put any untreated dirt in along with the sand. And we probably did "overkill" with the pramatol granules & made very sure they were completely wetted since it's water activated. That's the one step she's not 100% sure about ... whether or not their pramatol was wet before the liner install. I knew about the problems they had with nutgrass & didn't want a repeat. Of course, we live in a 60-year-old+ house with an obviously well-established yard of mainly centipede grass.
I told her this forum should be able to provide excellent advice! Thanks in advance for your help!