Cloudy water from old Zeobrite media?

[Big Easy]

We have a 32' round above ground swimming pool which was installed about seven years ago. I changed out the original filter with a Haywood Power-Flo Matrix Pump and the Pro Series Top Mount Filter (S210T - 44gpm). I'm satisfied with the performance of the pump and filter combo. However, when I installed the system, Zeobrite was all the rage. It's been about four years now. I haven't had too many issues so far, until this season. We had a few top rails replaced and the technician commented on the water being somewhat hazy/cloudy. He asked what filter media was being used and I mentioned the Zeobrite. He advised to replace it with the regular filter sand. We brought a sample of water to the place where we buy the chemicals and they tested it. One thing that they found was that the total chlorine level was .5 and free chlorine was .5, as well. They indicated this to be very low (if I understood correctly). The evening before the water test, I added six bags (6 lbs) of shock and six sticks to the skimmer. The water in the other categories fell within the normal ranges. The problem is that the water went from hazy/cloudy to so cloudy you can no longer see the bottom of the pool which is only about 52" deep. The place where I test the water has stopped selling Zeobrite altogether since they we getting too many complaints. After researching the issue on the Internet, I found that not all, but many people are experiencing problems with this media. Cloudy water conditions, fine light colored dirt that accumulates on the pool bottom not long after it's been vacuumed, etc... I read also that algaecides and clarifiers can have negative effects with the Zeobrite. The weather is starting to warm up now and no matter how much I backwash the filter, it seems like there is no improvement. I've already used way more shock this season as compared to previous ones. I guess my question is, am I better off having the Zeobrite replaced with regular filter sand? Any advice would be appreciated.

[PoolDoc]

1. I don't know if old Zeobrite deteriorates in performance. However, it's very likely that you may not have ENOUGH media in your filter. AG pool pumps are almost always too big for the sand filters they are coupled with; this leads to loss of media when you backwash. Having insufficient media in a sand filter *will* result in hazy water.

We don't recommend Zeobrite; we've never seen any persuasive evidence that it offered any benefits over sand. But we haven't seen a lot of evidence that it's worse than sand, either.

2. It's unlikely the Zeobrite resulted in the sudden extreme cloudiness. If any of the shock contained calcium hypochlorite AND your pool had high calcium levels, THAT could definitely cause the problems. Our recommendation here is pretty standard: buy a K2006, test your water *reliably* and *accurately* and tell us what you find. (Link to Amazon K2006 units and more in my signature block)

3. Low chlorine ALWAYS results in problems. We almost always recommend that you raise levels with PLAIN household bleach, at least until we've seen K2006 test results. Bleach may not be the cheapest source -- that varies from time to time and place to place -- but it is the form of chlorine with the fewest side effects (like calcium!). So it's the safest recommendation, till we know more.

4. If your media is low, you can add more Zeobrite OR you can replace with sand. I'm not sure I'd recommend mixing the two. That's not because I *know* it's a bad idea; rather I just don't know if it's a good one, and I tend to avoid 'mixes' of all kinds, till I know about compatibility.

5. Mixing various pool specialty chemicals is almost always a bad idea; many have severe side effects all by themselves, and worse ones when mixed. The only specialty chemicals we frequently recommend is polyquat (www.poolsolutions.com/polyquat.html) and then only if you need it.

[Big Easy]

PoolDoc - We had the filter media changed from the Zeobrite to sand. In addition, a chlorine demand (24 hour) test was performed and the chlorine level was very low. We added ten pounds of turbo shock and five pounds of super soluble chlorine and it appears after a day or so that the water is beginning to clear. Will take the water in for another test in another 24 to 48 hours to see where we stand. All of this rain that we've been getting in the mid-atlantic region isn't helping either. I do appreciate your help and advice. You always learn new things from people in the business.