What the heck could possibly be wrong with our pool?

Question

My mother in law's above ground 16,000 gallon pool has not been 100% clear this season and at one point was super green...Last year she replaced the earth filter that she had since she bought the pool (15 years ago) with a sand filter...my husband installed it and it worked fine...this year no such luck...we've tried every chemical and vacuumed and scrubbed the sides and bottom and even got the pool place to (finally) come out and exchange the filter for free...and their people set up the new one...it's been 4 days and there's no change...what the heck could be the problem? Has this ever happened to anyone else? If someone can come up with a solution that we haven't tried I'll really be suprised...

I know I said the pool company came out and replaced the filter...I was trying to suggest that they had also "tried everything"...We know about algea and chlorine and test kits--which by the way come out normal every time,,,we've shocked and added various combinations of chemicals...My mother in law has had this pool for over 15 years and is well aware of the proper care techniques...

Answer 1

A sand filter will not filter water as well as an earth filter: a sand filter will only filter particles 5 microns or larger, while an earth filter will filter particles as small as 2 or 3 microns. Also, a sand filter is ineffective if you backwash too often. Wait until the pressure climbs 10-12 lbs higher than normal before you backwash. Otherwise, the sand is "fluffed up" and particles can pass easily between the grains of sand. The sand needs to be compacted for it to work. Some people open the filter and spread some earth (d.e.) over top of the sand to help it filter better.

You can improve the filtration of a sand filter by adding a coagulant (clarifer) to the water, to the make the small particles clump together so that the sand filter can catch them. Also keep in mind that a sand filter may have to run 16-24 hours per day to do the same job an earth filter can do in 8.

All this, of course, assumes your water is properly balanced, chemically. Take your water sample to a pool store, and have them check free chlorine, combined chlorine, pH, total alkalinity, calcium and cyanuric acid. The latter two are rarely checked unless you specifically request them to. You should also have it tested for iron, copper and manganese occasionally, depending on your water source, and whether or not you've used a copper-based algaecide.

BTW, suggest you disregard the post that recommends you keep your chlorine level at 10 ppm - the recommended level for a pool is 1-3 ppm, but I would keep it as close to 3 as possible, to allow for unexpected heavy bathing load, storms dropping algae spores in the water, and your forgetting to check it as often as you should. 10 ppm will bleach your liner and ruin your solar cover - the bubbles will actually pop, and the plastic will turn brown and stiff.

The above recommendations are based on my 10 years of experience working in a pool store, including testing the water and diagnosing problems.

Answer 2

The green water is due to algae growth. Changing the filter will probably have no influence on this condition.

1. Check to ensure that no fertilizer or such like has leached into the pool.

2. Use a pH test kit to ensure the pool has the correct pH balance.

3. If you are using pool chlorine chemicals as opposed to an electrical chlorinator increase the dose.

Green water will often follow lightening activity or heavy rains but by attention to the above it should rectify itself fairly quickly.

Answer 3

After the pool turned green did you add a biocide to kill any remaining bacteria? If not I would recommend that you do so. Be sure to flush the pool equiment, and throw any leaf catchers into the water as well, to disinfect them.

Also, I would recommend adding a surfactant to the pool to propmote agglomeration of the particulate in the water. This will help filter out the cloudiness in the pool I use a product called Polysheen, and it really increases the efficiency of my filter system.

Answer 4

I would switch back to an earth filter - it always worked for us. But on the plus side it may just need more time to clear- my pool took almost two weeks to fully clear...just make sure that you have plenty of chlorine in it - that's what kills the algae (the green)

Answer 5

try these websites

www.poolforum.com or
www.poolcenter.com

My husband gets great answers there all the time

Answer 6

granny pissed in the pool