Change sand if baqua conversion is done mid winter?

[joefishengineer]

Thanks for this fantastic site! I have read through many posts on baqua conversion, but still don't know if I should change the sand. Previous owners had the sand changed every year because they used baqua. I am new to pools but have read extensively on TFP and feel very comfortable with the chemistry and basic skills thanks to all of you. I kept the pool open and running and let all the baqua dissipate (based on pool store measurement). In fact I waited too long and a January warm spell gave me an algae bloom. When I shocked the pool it turned brown for a few days and took a week to completely clear, but there was zero goo so I am thinking it was just algae instead of conversion colors. I have added bleach or calcium hypo to keep the chlorine level up and plan to install a SWG when the water warms. My TA, PH and CYA levels are all now within the guidelines on TFP. My pressure runs 19 psi on recirculate and 21 on filter when clean (just after backwash). I Back flush every couple of weeks when pressure gets up to 25 or when I need to drain due to rain. With my pressure not showing any signs of clogging and never seeing any goo, is there any compelling reason to change the sand? If so, can someone explain what I am missing? Is my thinking correct that a 2 psi difference in recirc and filter is normal?


Thanks again to all!

 

[Leebo]

First off, WELCOME TO TFP!!!!!!

I would suggest opening the filter up and looking at the sand closely. If you see any clumping or "goo" you'll want to change out the sand. Almost always this goo is created as the chlorine breaks down the Baqua in the water. If you have any of this goo and don't change out the sand you'll likely see reduced filtering and an increased CC level. If however you don't see any goo in the sand and are consistently running a 0CC level.......well then you got VERY lucky.

 

[kimkats]

It also would not hurt to do a deep clean of the sand even if it looks good just to stir things up and make sure.

Deep Cleaning a Sand Filter

Let us know what you find when you open it up.

Kim

 

[joefishengineer]

Thanks! I will take a look this weekend. Hopefully there won't be any since you baqua levels were zero. I suppose there could have been some lingering in the filter though.

 

[duraleigh]

I would eyeball the sand. The conversion instructions clearly call for a sand change.

You may have partially cleaned your sand just by continued use or it may still need it. The choice is yours but at the very least you need to open up and look at it.

 

[joefishengineer]

I opened up the filter yesterday and the sand looked pretty good to me. It was dirty as expected, but not hard and compacted. No goo! I could easily dig my hand in to it. You can see the pic that I attached. Of course, I am new to pools so I don't really know what bad sand looks like. Since I had it open, I went ahead and changed it so I don't have to worry about it. I did want to follow up with this post so that others thinking of swapping can consider that in my case, all the baqua was out of the pool and I ran it for a couple of months in winter to be sure. I did use the baqua shock occasionally, but it dissipates quickly. This let me keep algae at bay without using sanitizer. Of course the temperature did most of the work. If I were going to do it again, I would do the same thing and not worry about the sand if the pressure difference between recirc and filter wasn't much (2 PSI in my case). Note that I had backwashed before opening the pump so the sand is a bit out of place. I also had to pump the water out because the drain was clogged so that factored into why I changed the sand as well. Thanks for the help! Come on summer!