Help! I've basically installed a brand new filter and still no results!

I have a 5,000 gallon vinyl liner inground unheated pool with a copper diode ionization system (Carefree Clearwater) and a Hayward 166T sand filter. This system was installed in 2011 in a weekend house in WV. The pump is a Pentair Super Flo variable speed pump, which is a new pump I installed at the beginning of 2020. All was going well with the system until late August of this year. Maintenance typically involves balancing the water chemistry with muriatic acid, TA Up, and calcium chloride, and then adding shock once every few months if algae starts to get a little out of control. The ionization system does the rest of the job pretty well. This summer, I went away for a month, and when I came back, nothing I did cleared up the algae. I hypothesized that friends who stayed there while I was away may have messed up the filter. So I changed the 3 year old sand to new pool filter balls and swapped in a brand new multiport valve and lateral assembly. I fine-tuned the water chemistry and double shocked the pool. As usual, the green algae died and turns to brown, but the filter is not doing its job. The pool has a fountain which will has in the past shown reduced flow as the filter gets more dirty - but this doesn't seem to be happening now. Further the filter pressure gauge shows 2 PSI and does not increase as the pool algae gets worse. This is a big mystery to me considering that the filter itself isn't that complicated of a device - and I've replaced most of the key parts! Any ideas for troubleshooting this are much appreciated.

FYI - the pool chemistry is within reasonable limits: VW_pool_chemistry



Gold Supporter
TFP Guide
Jun 16, 2019
Hey Jahoos and Welcome !! You’ve been playing a dangerous game with the copper. Copper is a great algae inhibitor, but does zero for sanitation. You’ve really only been sanitizing through pool when you decide it’s time to shock it and most of those times it was probably too little/too late. Algae is an unsightly problem but relatively safe for humans. Human to human transfer of bacteria and viruses are the main concerns for sterilization. They sell these copper systems as ‘never have to worry about algae again’. (Which you’ve seen is only half true) and everybody who gets suckered never even thinks about all the other ickies that fester. You have been fortunate that you guys didn’t get rashes every couple of weeks because that’s usually what gets people off the copper. To manage somewhat as long as you have might be a mew record. But the key to these copper systems is to still add the full amount of chlorine to sanitatize everything but the algae. At that point, the copper is useless because the chlorine kills the algae too and the residual chlorine keeps it *all* at bay. Long term, the copper eventually stains pool surfaces, swimmers hair turns green and pool equipment corrodes. You may have experienced some of this, or you were just lucky, but either way you need to make drastic changes going foward. We can show you how.

98% of the filter problems that bring us new members turn out to be an algae problem that can only be cleared with aSLAM Process

read up on ABCs of Pool Water Chemistry to see what we are all about. Just pain science and facts. No Voodoo magic and simple, cheap, over the counter chemicals to keep the pool invisibly clear and more importantly, all of your swimmers safe.

once you check out the links and get an idea, fire off any questions and we have tons of good folks to guide you in your journey.

Again, welcome and you sure landed in the right spot.


Gold Supporter
TFP Guide
as you have now found those systems dont really work
you are better off using liquid chlorine or a salt chlorinator
comments such as chemistry is within limits are meaningless
your attached chart shows your chemistry is not meeting TFP criteria as there is zero fc
good luck


Gold Supporter
Jul 2, 2018
Austin, TX
Here’s an analogy for you. Algae is like the canary in the coal-mine. Its growth is telling you that your chlorine is too low (in your case 0). What you are doing is the same as just removing the canary from the coal-mine. Yes, that would save canary lives, but would do nothing to address the real problem...poor air quality.

You are defining your ”problem” incorrectly. Algae growth is a symptom of the problem. Again, the problem is you don’t have chlorine in your pool. It is not safe to swim in currently.


Gold Supporter
TFP Guide
Nov 12, 2017
Central California
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Hey Jeff, welcome to TFP! Glad you found us, and sorry about your pool issues. Like a lot of people that come here, a lot, you seem to be under the impression that algae happens sometimes, and dealing with it once in a while is just a part of normal pool maintenance. It doesn't have to be so.

Most of us here that use TFP methods NEVER get algae in our pools. Like EVER. The few that do, usually have themselves to blame, for getting a bit lax with their pool chores. It's very easy to maintain pool water that is 100% algae free, year round, and is 100% safe for you and your family. The TFP method of care also happens to be the best for your pool, and costs less than any other method, because we don't use "magic" potions from the pool store, just simple, cheap, readily available chemicals (like plain ol' bleach and baking soda, etc). I know how crazy that sounds, but our MO is based on real, reputable science, and is NOT based on a profit model. If any of that sounds interesting, then have a good look at what we do here. If you get on board, we can quickly help you solve all your pool issues for good...

PS: Your pool is not actually "within reasonable limits" at all, and in fact is not safe to swim in... So even if TFP is not for you, please do address your inadequate sanitation methods some other way...
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