New pool owner with some questions

I recently bought a house with a 20x40 in ground pool. The previous owners used Baquacil. The vinyl liner is 10+ years old and in decent shape. The local pool store said that they do not advise changing from Baquacil to chlorine if Baquacil has been used for more than 5 years. Is their recommendation valid? If it is possible, I would like to change to chlorine, but would not do so until next year since I have already lost almost a month of pool time getting it opened.

My current issue is that the pressure in the Hayward Perflex DE filter rises from about 8-10 psi to 20 psi in about 2 back to about 10 psi but then goes back up to 20 psi in about 2 hours again. If I let it continue the flow rate goes to almost nothing. I assume that this is not normal. I did have an algae issue that has been resolved using Alum. I then cleaned the filter with Leslie's DE filter cleaner and spraying the fingers with a hose until they looked clean. I am now at a loss as to what might be causing the problem.

Thank you for any ideas that anyone has.

There are lots of claims about what's hard on liners, and what's easy on them. But the ONLY things I've been able to actually confirm with engineers at the few companies that actually manufacture the vinyl sheet (which they sell to pool liner manufacturers) is that
1. pH below 6.4 is hard on liners, and tends to cause them to swell.
2. pH above 8.4 will, over a long period of time, make the liner less flexible.
3. chlorine will bleach the COLOR or pattern from a liner, and some liner colors are MUCH more susceptible than others.

I can tell you a liner that lasts 10+ years has done very well indeed. I would suspect -- but do not know -- that Baquacil is not has hard as chlorine on liners. I wonder -- but do not know -- how peroxide (BaquaShok) affects liners. I *know* that it destroys polycarbonate, used on pump and filter lids.

So, my guess is the dealer is making that claim mostly to protect their sales of a high-margin product (Baquacil) against a low-margin product, but that it might actually be true. However, if I was wagering money (and not risking a liner), I'd bet 5:1 that the dealer is just 'selling'. I'll see if Waste knows anything, though.

Regarding your filter -- Baquacil is NOTORIOUS for gumming up filters. You can try some of the Baquacil line of filter cleaners, and see if any of them help. (They'll help the dealer's bank account, but I'm not sure about the rest). DE filters can do OK with Baquacil, but ONLY if you NEVER let pool water circulate through the filter without an adequate pre-coat of DE.

Quote:

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Originally Posted by PoolDoc

I'll see if Waste knows anything, though.

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And just in case you're wondering what that means, Waste aka Ted is a member of the Pool Forum Support Team and is a pool installer. He is a very valuable member of our team and we are very fortunate to have him!

Welcome to The Forum!

I'm sorry but I have almost no experience with Baq (there were a couple pools in Richmond ~20 years ago that I knew not to add chlorine to, but that's about it).

Sorry.

Ok. There you have it. We 'officially' don't know, whether your pool guy is correct, or just messing with you.

Sorry we can't help more!