Problem with water being cloudy/murky.

Hi,

First time poster, but I have lurked around this and the TFP forum before.

First, a little intro. I live in SE Texas, near the coast, about an hour from Houston. I have an inground pool, approx, 18,000 gallons. Gunite/plaster. Had the plaster re-done last year. My filter is a sand filter, my pump is a 1-HP pentair whisperflo. I installed the pump/filter myself around 2006, before that I had a DE filter.

I bought this house second hand, the pool was originally installed in '88 or '89. Through the years I have done my fair share or more of upkeep..actually way more than I would like.

The big problem I have been having this year is that the water just stays cloudy and murky. I have tested the water myself several times, the pH and Alk. are all within the normal ranges, as is the hardness. It seems that the water will try to clear up a little, and then go right back to being cloudy. I'm using tons of chlorine and backwashing the filter when it needs it (going by the discharge gauge).

I have several thougths on the causes. One thing I'm suspecting is that my filter is not working correctly either due to internal problems or maybe the sand needs to be changed. I changed the sand once before a few years ago but it didn't really help. I have heard that the selection valves get messed up and let the water bypass the filter, or at least a side stream.

Second thought is that it's algae that I'm not clearing all the way out. Normally when the pool gets infested with algae it turns green and you can see it on the walls /surfaces. This really looks more murky than anything else.

Other thoughts are that my chemistry is not right and my tests are wrong. I'm going to take a sample to have checked this week, but other than that any tips or anything would be appreciated.

It's really kind of hard to tell much without water testing results. Post those when you get them and we'll take a look. Consider getting yourself a good test kit instead of relying on a pool store to test for you. We like the Taylor K-2006 or 2006C which is the same kit with larger quantities of some of the reagents. Click on the Amazon link in my signature. If you order through that link, the Pool Forum makes a little money on the sale which helps keep the forum online. Only buy if the seller is Amato Industries as some other sellers are substituting the K-2005 which you do NOT want.

It isn't necessary to change the sand. I'm on my 11th season with mine and some people are going much longer with theirs than I am.

Re-post with readings and we'll go from there. Welcome to the forum!

Thanks for your quick reply. I do test my own water, and right now the pH is within range, as is the hardness/alk. I don't have the numbers sitting in front of me as I'm away at the moment but I will have them tomorrow. The only reason I'm taking them to the pool place is to see if they get anything different. They always try to sell me some stuff I don't need but I never fall for their tactics.

I'm really at wits end with this pool. Last year after having the plaster and skimmers fixed it was a dream for a few months. Very simple and easy maintenance, chlorine stayed good, everything was great until the end of the season when I started having problems. Now i'm back to my nightmare. I didn't think that the sand went bad but perahps I'm not flushing it throughly or maybe I need to run my pump longer? Right now I'm running it 12 hrs per day with an in-line chlorinator but the water never clears, even when I keep the chlorine levels high for days.

Also I forgot to add that I am considering going back to a DE style filter. I have heard that they work much better, and now that my skimmers are functioning properly I would be able to charge it correctly ( my skimmers were non-functional until last year. Long story). Any thoughts on this?

Tell us how you are testing, and what the numbers are. (If you've hung around here & TFP, you know we're probably going to tell you to get another kit, unless you have one of my old kits, a Taylor K2006 or the TFP kit!)

Tell me what make / model of filter you have.

I'm just guessing, without that info, but my guess is you've installed a filter that's too small, and have blown most of the sand out, when backwashing.

(BTW, Lisa, sand normally is NOT present in backwash. When it is, the sand is not properly graded OR the filter is too small. Of course, that describes more than 3/4 of pools with sand filters, so I guess it is "normal" in the statistical sense. But it's not 'right'!)

Ben

When you post the numbers, please include the free and total chlorine readings. (just to rule out an algae issue)

You can also supplement your sand filter with ~ 1/2 cup of DE if the cloudiness is being caused by something too small for the sand to catch.

Thanks for your replies everyone. Ok, had the water tested (professionally today), and the results pretty much match up with my home tests. Here are the results:

FC 2.1 ppm
TC 2.1 ppm
Combined Chlorine 0.0
pH 7.6
Hardness 250 ppm
Alkanity 67
CYA 10 ppm
Copper 0
Iron 0
TDS N/A

I was using a Taylor kit for chlorine and pH, and then a different kit for the Alk and hardness (blue box kit, don't know the brand).

I have a Tagelus 60D sand filter, rated for about 60 gpm, my pump does somewhere around 30 gpm. I installed the pump and filter myself.

Quote:

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Originally Posted by PoolDoc

Tell us how you are testing, and what the numbers are. (If you've hung around here & TFP, you know we're probably going to tell you to get another kit, unless you have one of my old kits, a Taylor K2006 or the TFP kit!)

Tell me what make / model of filter you have.

I'm just guessing, without that info, but my guess is you've installed a filter that's too small, and have blown most of the sand out, when backwashing.

(BTW, Lisa, sand normally is NOT present in backwash. When it is, the sand is not properly graded OR the filter is too small. Of course, that describes more than 3/4 of pools with sand filters, so I guess it is "normal" in the statistical sense. But it's not 'right'!)

Ben

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OK, now we see that my alk and CYA are a little low, but not super low (except CYA). I will work on those two tomorrow. I don't think I have lost my sand, but I have plans to take the sand filter apart tomorrow. The dP on the sand filter rises generally over time, as you would expect. I backwash normally ever 1-2 weeks, and you can tell if the filter is getting plugged because not enough water is coming through the pool return jets.

Thanks for your advice and input.

OK, I ordered the Taylor K2006 kit. Today I'm adding baking soda and CYA to get those numbers up a little, and then I'm taking apart the sand filter.

Keep in mind that if you add the CYA through the skimmer, and then take the filter apart, you're going to lose your CYA...it takes several days for it to sit in the filter and dissolve. If you added it via sock, then you should be okay.

I wouldn't worry about the TA for now--get the filter working, get chlorine in the pool, and once it clears up you can tweak the rest of the numbers.

Janet