I have a Zodiac Duoclear system. I didn't ask for it, it came with the pool, and I didn't know about this website when I bought the pool. I have several questions - please and thanks -

1. Is the mineral cartridge adding things to the pool that I don't really want (like metals that will cause staining etc.). I can't run the system without the mineral cartridge unless I can find some way to seal the opening the cartridge sits in(or run an old cartridge that has hopefully run out of minerals).

2. Zodiac recommends chlorine as low as 0.6 From the owner's manual "1.0 – 3.0 ppm. This level may be lowered to 0.6 ppm with the use of the Nature2 cartridge."

They also recommend CYA from 30 to 100. Looking at the CYA chart, the mininum chlorine level at 30 is 2.2. I'm guessing I should ignore Zodiac's recommendation and use what the chart recommends. My chlorine has been around 2.5 or so all summer, and my CYA was 35 when last tested.

How can they actually recommend this? If I went as high as 50 or even 100, and kept the chlorine at 0.6, would the chlorine even be effective?

3. Alkalinity they recommend 100-120. I'm keeping it closer to 80. Is this OK?

4. PH they recommend 7.2 to 7.6. Mine always creeps up (salt pool etc.) and I use muriatic acid weekly to keep it around 7.4. Is this number OK?

The main reason I'm asking this is because my pump and filter basket are getting a yellow/brown tinge to them and the eyeballs in the jets are very yellow, but oddly, not on the part of the eye that's exposed, but the part that is behind (hope this makes sense - only if I swivel the eye to a different direction so the part that was hidden becomes exposed, do I see the yellow/brown stain. The skimmer itself (and the face) and my very wide white stairs are still white.

other than your duo-clear issue (not sure how to fix ) your numbers seem fine other than you need to follow the CYA/FC chart. Do you have a recent FC/CC test result? Have you performed an overnight FC loss test?

Sorry, just edited in some missing information. I haven't been following the 0.6 recommendation. Recent water test was good (don't have the figures - I'm at work). Haven't done overnight loss (don't have a decent test kit, and apparently no one will ship me one because I'm in Canada??)

You can get the K2006 from Apollo

http://piscines-apollo.com/cubecart/index.php

How can they recommend the .6? Good question.... good that you are ignoring it.

Your staining description sounds just like what happened in my pool when I used the 'frog. I would consider a) removing the unit from the plumbing line or b)keeping an old cartridge in the system but I don't know truly how "empty" they get or what adverse affects there are from leaving it in.

The Duoclear is a mixed "mineral" and SWG system. As such, it suffers from all the usual disadvantages of a mineral system (ie metals in the water that can cause unsightly stains) and makes the associated marketing claims (such as the low recommended FC level). We don't recommend using any mineral/metal system. You can disable the mineral half of the unit by simply removing, or not replacing, the mineral cartridge.

Thanks for the help. Due to the design of the Duoclear, I can't run it without a cartridge as the cartridge actually seals the opening of the unit. I guess I might have to resort to using an old, hopefully used up, cartridge, or figure out some way to seal the opening without a cartridge (I suppose I could cut out the actually cloth bag that has the 'mineral stuff' in it and just keep the plastic exterior of the cartridge.

I put an Aquapill #4 - http://www.smartpool.com/website/aquapill03.html in the pool and the stains are disappearing quite nicely. Wish I had taken a before/after pic. The pill had some sort of powder in it - I had to pop a cap open, fill it with pool water, puncture it and throw it in the skimmer. The instructions suggested lower the PH to 7.2 and the FC to 1 (IIRC). What do you think this stuff is?

I hope it's ok to post the link above...?

Overpriced ascorbic acid.

Luckily I got two of them for free, as the pool store is not carrying the product anymore and I'm on good terms with the salesman who sold me the pool. They had all sorts of Aquapill pills in the warehouse, but only two of the #4 stain remover, which I now have.

I'll definitely research ascorbic acid on this site if I need to remove stains again (which I hopefully won't once I deal with the mineral cartridge in the Duoclear).

Thanks.

Thanks for the Apollo link. I'm now $160 CDN dollars poorer. But I can't wait to play mad chemist.

Looking at my cartidge, i'm pretty sure I can remove the yellow cap from it and then it will seal the duoclear up. Did you ever end up trying that?

Actually, I just opened up the cartridge and removed the bag from inside. The bag is like a fine nylon mesh and was full of little balls (like small ball bearings). Some were white, some where blue if I remember correctly. Then I just dropped the cartridge back in (with the bag now removed) and this way I was able to still seal the Duoclear vessel properly. This upcoming season (I'm opening this week) will be my first full season without the mineral bag, so I'll see if the stains return. I removed them last fall using an ascorbic acid treatment.

OK, I've done the same. I'll post back later this year on how things work out.

heinz,

Welcome to TFP!

Just thought i'd report in half way through the summer. So far no problems. Water is crystal clear and no chemistry problems.

I've updated elsewhere in a post about removing the mineral bag from the duoclear. My results are the same as yours, and the stains that I mentioned have NOT returned.

Summer is well over. Just thought about this thread. 0 problems all year with mineral bag removed.