ok, so heres my problem, a while ago i noticed some algae starting on the side of my pool, or i did a total clean out of my de filter, which is a pentair 4000 series smwp 4060. i put it all back together and everything is looking like its fine. i go out back a few days later a notice the entire pool is now green and my waterfall and baracuda are no longer active. i check the pump and its running, so i clean out the basket, but still no avail to fix the problem. i clean the filter again and recharge the de, but within about 30 minutes of turning the pump on, the baracuda slowly comes to a stop and the water fall stops as well.... getting pretty frustrated, i clean the filter again, still with the same results. no my pool has turned into a small scummy pond with bugs living in it. ive shocked the water and still no good... not really sure what i should do... i pull out the de grids and run the system without any filter elements what so ever and the problem doesnt come back. is it a problem with my filter girds? are they just plugged up and need to be cleared? can they be cleared? should they just be replaced?? any help is much appreciated as to the fact that im so fed up with it, im about ready to just buy a completely new cartridge filter. please help!!

Hi, welcome to TFP! It sounds like you have a 2 part problem. Algae is the result of insufficient chlorine. If you could post a complete set of test results we would have more specific advice to give to clear up the algae. The algae may be clogging your filter and barracuda enough to affect performance. Please read these articles defeating algae and how to shock your pool to familiarize yourself with the shock process.

I understand about shocking a pool, but theres no point in shocking a pool if the filter isnt working properly, correct? otherwise the shock just kills everything but it doesnt go anywhere since the filter isnt working properly... im less concerned with my pool chems right now, and just more concerned with getting the filter to work properly... is it possible that the algae is clogging up the de filter girds? if so, how do i clean them out so they can work more efficently?

Welcome to TFP!

There is no indication that your filter isn't working properly based on what you have explained thus far. There is however, a possibility that algae is clogging the grids and affecting performance and unless you take steps to clear the algae, you cannot eliminate this as the causative factor.

Shock is a process, not a product that you add to a pool. By shocking your pool, you are raising the level of sanitizer, which in most cases is chlorine, to a level which provides the best disinfecting power based on your CYA level. This is why zea3 has asked you for test results. Without accurate test results, we cannot help you as we don't know what areas of your pool water chemistry need the most attention right now. Trust me...we have thousands upon thousands of people who have shown up here on TFP having lost all hope of having a clear and sparkly pool ever again. But 100% of the ones who listen to us and follow what we teach here at TFP have met with success in solving their pool problem(s).

Please give us your FC, CC, pH, CH, CYA, and TA. In your signature line, include your pool specs. Look at mine for an example of what you need to put in there.

Yes the algae is clogging the grids. It's just going to keep getting worse until you get rid of the algae. You've got to get the chlorine up and hold it there 24/7 until the water is clear. It's going to require quite a bit of filter cleaning in the process.

That happened to me before. After I hosed off the grids, I left them out to completely sun dry to kill the algae on the grids. Then I shocked the pool and filtered it for a long time. It worked for me.

So basically I have to get the chlorine levels up and then clean the filter, run it till its plugged, clean it again, run it till its plugged and then clean it again until its all clean?

Pretty well. Remember that with algae your pool will eat chlorine rapidly, so you may have to test and add more as often as every hour at first. Then you can slow down as your test results show that it is holding at shock level for your CYA level.

Ok. I would post me chem levels but all I have is a basic chlorine/ph level test. I also moved in with the pool here already, so not really sure on all the specifics of my pool.

Another thing to consider is that backflushing doesn't get rid of all the DE. The rule of thumb is 80%, but I think that's overly optimistic. And if you're adding the full amount of DE each time, you're overloading it. The screens and the space between them get completely blocked. I'd say a teardown is in order. It's not all that hard. Some very basic hand tools and a tube of aqua-lube. use-and-care-for-de-filters-t4086.html goes into some detail. There are also videos on youtube showing it done.

The next thing is a proper test kit. You can't really shock unless you know the CYA level, and the color-matching test is not good for this. It doesn't read high enough. Cut right to the chase and go to http://tftestkits.net and order a TF100XL. I also recommend a speedstir.

Well ive never really backwash it... I typically do a full teardown... But I went to the local pool supply and he said I havent been using enough de. So well see what happens now after a full tear down, and the proper amount of de. I also have tge test strips but not sure how well they work?

They don't.

Ok, didnt think so... Ok so this morning I did a full clean of the grids, used the right amoumt of de. Within about 2 hours or so, the pressure went up and I lost suction and return. I backwashed it and recharged it and again within about 2 hours the same thing happened... I havent had a chance to backwash it again, but is this all because the algae or somethimg else Im doimg wrong?

Nope you're not doing anything wrong - everything is working right! You're going to be cleaning the filter a lot until the pool is clean.

Ok sounds good... Guess I better go get more de....

You ARE shocking right? Not just filtering? It's not clear from reading the last few posts. You REALLY need a good test kit to do this correctly.

Right below your first post, zea3 posted links to a couple of pool school articles detailing the process.