Brown gunk on the bottom of pool

[rox29160]

I tested my pool water with the OTO kit I have when I got home from work. The chlorine level is somewhere in the 1.0-1.5 ppm range, which is where it usually is unless it has recently rained. The ph is a little lower than my kit says is ideal, but only by a little. I would say it is around 7.5. The kit says ideal is 7.6. It is hard for me to match up the colors exactly which is why I was already contemplating buying one of the Taylor kits before Watermom suggested it to me in the previous post. The chlorine and ph levels are pretty consistent. It doesn't matter if I test in the morning or in the evening like I did tonight. I don't seem to be losing much chlorine. I only run my SWCG for 2 hours per day. Any more than that and my chlorine readings get up around 5 ppm.

I double checked the tank on my toilet. The "brown" I referred to earlier is a brown ring around the top, at the normal water level, not the entire inside of the tank (if this makes a difference).

I also got in the pool tonight and investigated the brown "gunk" a little. The walls of the pool are NOT slimy at all. I have read that this is an indicator of algae in other threads. The brown stuff looks kind of like dirt, but when you try to pick it up with your fingers, it disintegrates. It is slimy almost like the slimy mud in the bottom of a river. I don't have a lot of it. It is just in small isolated spots on the bottom of the pool about the size of quarters. I tried vacuuming it up, but I have the cheap vacuum that came with the pool. (the kind that connects to the garden hose and then catches debris in a little net) After tonight, I am sure that once the "gunk" is disturbed, it just washes right through the holes in the net.

Any help is appreciated. Thanks in advance.

[PoolDoc]

Could be dead algae -- have you had algae?

[BigDave]

I had better luck vacuuming finer particles with the Intex venturi-vac by adding a nylon stocking inside the filterbag. I cut the foot and leg 3 - 4 times longer than the filterbag, stuffed it in, and secured the open end of the stocking over the venturi-vac outlet with the filterbag drawstring.

[rox29160]

I am not aware of having any algae. My pool has always been crystal clear until this stuff started settling out a couple of weeks ago. After vacuuming last night, the stuff had settled back out again this morning.

Thanks for the advice BigDave. I had been wondering how to rig a makeshift filter onto my vaccum. I saw another thread where somebody used the stuffing out of a pillow, a bucket and a sump pump to filter iron out of their pool. Whether this is iron, algae or whatever, I need a makeshift filter to hook to my vaccum that will catch this "gunk" and not allow it to disperse back into my pool. I think the particles may be too small for even a nylon stocking. They seem to dissapear when you disturb them or try to touch them.

[famousdavis]

I used to have an Intex above-ground pool for years, with the same problem you've described. The problem wouldn't occur at the beginning of the summer, but by late July, the problem would appear every year. Turns out it was *pollen* that was collecting in my pool water! The only way I dealt with it was either empty out the pool every few weeks, or use a pool cover.

[rox29160]

Alright, I have finally decided to post my test results after receiving my new K2006 test kit. I've had it for a couple of weeks, but wanted to make sure I was getting consistent results before posting them on here. I still have the brown stuff settling on the bottom of my pool every couple of days. (Vinyl Intex above ground, approx 5,000 gallons, Intex SWCG)
Test 1 (WEEK 1)
FC 2.6 ppm
CC 0.2 ppm
PH 7.2
TA 90 PPM
CH Test started Purple instead of red
CYA DOT did not disappear

I added 1/4 pound more of cyuranic acid and waited a week before testing again.
test 2
FC 2.5 PPM
CC 0 PPM
PH 7.2
TA 80 PPM
CH 50 ppm ?
CYA Dot still did not disappear but solution is at least blurry this time. I would guess it probably around 15 ppm.

Regarding the Calcium Hardness, I tried a couple of different things. Per the instructions of the K2006 kit, I tried adding 5 drops of titrant first to tie up the metals in the test sample then the buffer and indicator. Doing this the solution was blue before adding any more titrant. Then I tried adding only 3 drops of titrant to tie up the metals before starting the test. Doing this, the solution started red and I was able to conduct the test until the solution changed from red to blue. This way yielded 50 ppm, but I don't understand chemistry so this may not be acceptable at all. Some body please advise.

Since the CH test started out purple does this mean that I need something to take the metals out of my pool water? I have about another 1/4 pound of cyuranic acid. Should I go ahead and add all of this? I already have 3/4 pound in there now. The SWCG book originally told me to add 0.4 lbs which didn't even register with the test kit. One more thing, there have been a couple more sets of test results in which everything was pretty much identical to these. After adding the stabilizer, the TA seemed to drop, is this normal? How much baking soda / soda ash do I need to add to raise it?

Thanks in advance for any and all help.

[BigDave]

Your TA is fine at 80, If you pH isn't moving too quickly, I wouldn't worry about it.
I would add the rest of the CYA - you're still under 30.
You might want to bump your pH a bit with a little Borax ... but maybe not, do you find that you pH rises from using your SWCG?
You don't need to worry about CH in a vinyl pool - It's strange that your test doesn't work the way it should but ... I haven't done the CH test on my water 'cause it's meaningless to me. I suppose if my water was cloudy I might check.
Regarding the brown dust (and I don't know if this would help), I had a robot cleaner for three years I ran my Intex donut - it saved me hours as my yard is tree-covered. The filterbag is pretty fine - it might help - but $300 is a good price for one. It only lasted three years but I liked it so well I bought another this year.