Why won't my pool get clean?

[chem geek]

mohawk,

Just a reminder that if you want to lower your TA you need to lower your pH. Aerating at higher pH is not nearly as effective. See Lowering Your Alkalinity for more details on the correct procedure.

One thing you can do is to take some of this "brown" stuff with pool water and put it into a bucket that you keep in the sun (which will get rid of the chlorine eventually). When the chlorine is gone from the bucket (i.e. FC measures 0), cover the bucket with cheesecloth (possibly folded over to be doubled) or something that will let it breath and let some sun through, but will prevent any dirt from blowing in. Then see if the brown stuff grows in the bucket. If it does, then it's algae. If it doesn't, then it *may* be dirt or could be that we just aren't giving it an environment it likes enough.

If you have a microscope, you can fairly easily distinguish between algae, dirt and pollen.

If anyone has any ideas for a simple test to distinguish algae from dirt or pollen and doesn't involve a microscope, please chime in. It seems that this is a pretty common question to get answered, but unlike green algae that is easy enough to kill with chlorine, mustard/yellow algae is heartier so it's harder to tell from normal shock levels if it's algae or not.

Richard

[matt4x4]

My basic test for Algae vs dirt is the touch method - meaning, touch it and see, if it's slimy, 95% chance it's algae.
What you're describing does sound exactly like the trouble algae I referred to back a page. If you're getting it on the walls, it's another sure sign, dirt follows the laws of gravity - meaning it'll go straight down - algae, being a living organsm doesn't have to follow those laws. (like spiderman)
if it's first showing in the areas where less circulation exists and then looks like that area is growing, once again, a likely sign it's algae.
Dirt will keep accumulating in those areas too, but won't really grow it's deposit or settling area into water that's moving more adjacent to the stagnant water.

I've also tried this little test with this particular algae as well.
In my case it always starts on the side of the steps away from my return jet (bad circulation area).
Turn off pump to stop water movement
I've done this from outside the pool and it's MUCH easier because I have a "grabber" (for other purposes), but I don't expect everyone to own one.
You could also rig a broom handle with something like a stiff wire that will support the container for you.
Try taking a baby food sized container full of bleach into the pool - you can keep the lid off because keeping it upright under water seems to leave the bleach in it if it's moved really slow.
slowly move towards the problem area so as not to ciculte the water near it.
Once centered about 1 foot above the area, slowly flip the container allowing the bleach to settle over and onto that spot.
Come back 15 minutes later and see what the spot looks like - if it's dirt - like clay dust, it'll look the same, if it's algae, the color likely changed allready and it might be getting cloudy - recheck at half an hour after.

[mohawk]

Well I ran the pool rover tonight and had my son get out his scope. I can't find any pics of algae so I don't know what to look for in the scope. Nothing moved-and it looked like dirt. I took a water sample in today to the local store and they said no green-black-mustard or slime,mold algae. Although I have some cc. I showed nothing(cc) when I ran my own test. This is really baffling me. I read else where on the web that some suggests using sodium bromide or ammonium sulfate along with chlorine. Any thoughts on this? And if I swim in a pool that has this, will I get sick?

[chem geek]

If it were algae, then it would have some semi-transparent parts to it, especially near the edges. If it were dirt or pollen, then it will look pretty solid. It does sound like you've got some sort of reddish dirt in the pool. In addition to the excellent tests that matt gave, you could also just have a bucket of fresh water near the edge of the pool that gets a lot of this stuff and just see if the bucket of water gets it too. I'm betting that it's blown in dirt at this point. You didn't report any unusual chlorine demand.

Since you were able to scrape up some of this stuff, why not put it into a small container and add some concentrated chlorine to it as matt suggested. If it's algae, it will definitely discolor and turn more gray. If it's dirt, it may not change (you can take some dirt from nearby the pool to see how known dirt reacts to concentrated chlorine).

Richard

[mohawk]

I put 1 gallon of RO water in a bucket and then rinsed out the pool rover bag in it. Next I put 1/2 c of 6% bleach in and no change once the sediment settled. I kept adding bleach to see if there was any change and so far after 2c it's still the same color. I used a spoon to dip out the sediment and it looks like sand-very small and fine. The only thing that changed color was the grass and tree stuff that blew in-that changed to white. Maybe I'll try putting something on the return to see if sand is coming in from the filter.

[rilesworld]

mohawk,

I believe the stuff in my pool is some sort of silt/pollen as well. After shocking heavily for 4 days this brown silty substance still finds its way to the bottom the day after I vacuum.

I may take apart my sand filter (which has never been done) to visually inspect the sand and see if any maintenance is needed there. Otherwise I may try a filter sock or else I will just live with it and eventually the vacuuming and backwashing will get it out.

BTW, maybe this is just more pollen, but lately I can see a bunch fine white particulate on the surface of the pool. You can only see it if you catch it at the right angle. This is different than the intial pollen explosion, becuase then I was getting a green film on everything. The cars would be green. Now I am not seeing this green film on the cars, but this white particulate is clearly getting into the pool.

Oh well, its not really effecting the pool any, in fact it was a great weekend of swimming.

Riles