Why won't my pool get clean?

[rilesworld]

I recently bought a house with an IG vinyl lined pool. This is my first year maintaining the pool. This may be a silly question, but I am having trouble getting my pool clean (it's clean, maybe I should say sparkling). We have had quite a bit of silt, pollen, leaves, etc. in the pool this spring, and we vacuum about once a week. However, everytime I get done vacuuming some of the silt seems to return the very next day. Is this silt that just gets suspended during the vacuuming process (stirred up) and then settles back down the following day? Is that typical? I try to be careful and go slow, but sometimes I have to scrub to get the silt up.

My other thought was that I am actually vacuuming up the silt, but it is just not getting filtered out and then ends up back in my pool.

Riles

[matt4x4]

if you have to scrub a bit to remove teh "silt" then I highly doubt it's settled silt - please read:
http://www.poolforum.com/pf2/showthread.php?t=6954
it should explain what you should do.

[rilesworld]

I have read that post before, and was curious about that type of algae. Is there anyway to determine whether it is silt or algae (without a microscope). I would hate go through the extreme shock process if it wasn't necessary.

BTW I have a couple of other points. The bottom of the pool does feel a bit slimy (bad news), but this hasn't seemed to get any worse over the past month with me maintaining 3-6ppm Cl. It just won't go away. In other words, I don't get the impression that anything is multipling. Not sure if that information is useful, but it might help.

Riles

[mohawk]

We've had this same stuff since the pool was installed last year. I always thought it was dust and dirt. We had to dig out around the pool last year for code and now the grass is finally growing in, but I still get this dust the day after I vacuum. I thought maybe everyones' pool was like that. What can I say, I'm a newby. I still have a bottle of polyquat from last year. Do you think I should try that? I don't want to fade the liner. Right now I'm trying to get my CYA up since I had to drain this spring cuz of a hole. I always thought algae stuck on pool sides-that's what it does in my aquarium. Denise:confused:

[rilesworld]

The more I think about this the more I believe that it is indeed some form of algae. I do have a fair amount that clings to the walls and it is typically found in the low flow areas first.

I vacuumed yesterday evening and this morning brown deposits again could be found throughout the pool. Not a huge amount, but it has definately redeposited to some extent.

I am going to go ahead and shock as Matt has suggested and I will keep you posted with what I find out. As I said, I have had this issue for about a month, so if it clears with some heavy shocking then I can feel certain that it was indeed some form of algae.

Riles

[ivyleager]

Slickness on the vinyl surfaces ALWAYS means you're working on something growing in your pool. That's my first clue that I need to shock, which I do only rarely. Check your pool chemistry to make sure your levels are in range (CC, CA, TA, pH). If so, try these three things to sparkle up your water: 1) superchlorinate anyway to levels required based on your CYA, 2) run your filter 24/7 for the shocking, then knock it down to slightly over what you need to turn your water over; 3) use a skimmer sock ALL season. If you don't mind running the filter longer go ahead. I run mine from 8am - 6pm. I don't split up the time or need to run it at night. I'm not in California so that's not an issue. My pool ALWAYS sparkles. When it doesn't, then I know I have a problem.

Hope this helps.

CaryB
Anyone but Buffalo

[mohawk]

I've been thinking - if I add polyquat to the pool before vacuuming and the brown goes away, then I should assume it was algae-right? Then vacuum afterwards.

[chem geek]

To all posting with pool issues (rilesworld, mohawk): please post a complete set of numbers including FC, CC, pH, TA, CH, CYA. Otherwise we are really shooting in the dark here. The CYA level is very important to know as that will tell us how much chlorine is needed to battle this algae.

As for PolyQuat, it is generally not as effective at killing larger amounts of algae as it is for preventing algae from taking hold. This may be from this chemical polymer being easy to clump free-floating algae particles together and to block their ion channels, but that PolyQuat may be unable to penetrate below the surface layer of a biofilm of existing algae.

Richard

[tphaggerty]

I have had the slickness with my vinyl pool in the past. From my experience, you don't always need to "shock" (or super-chlorinate) to get rid of it, but you do need to BRUSH. Someone above posted that they get this in the less well circulated areas of the pool, and I think that is a good clue.

If you maintain your CL levels (meaning it is pretty steady, not dipping to 0, then back up), you can normally get rid of any slimy or slick feel by brushing the walls AND floor. If the feeling returns, you may need to shock and/or increase your normal CL levels a touch.

Richard has posted many times about CL not being as effective on bio-films (until they are removed) and I think this is a thin bio-film of algae. Once it is scrubbed/brushed a bit, the CL can get right to the vinyl and should keep it away at your normal levels.

[rilesworld]

My numbers were as follows before I shocked:

FC - 4
CC - 0
Ph - 7.5
CYA - 40
TA - 90
CH - 190 (not sure about this one, but I vinyl so I don't test it often)

I went ahead and shock to 23 ppm just in case I was battling the Yellow/Mustard algae that Matt4x4 refers to.

My Ph did go up quite a bit with the shock is that normal? It reads about 7.8-7.9 right now.

I brushed and added some DE to my sand filter. I already seems to have helped. Although I won't really know whether it was shocking or the DE that solved my problem. I guess I don't really care at that point.

What is a safe chlorine level to swim at?

Thanks,

Riles

[chem geek]

Yes it is normal for the pH to go up when adding chloriniating liquid or bleach. As the chlorine gets consumed or breaks down from sunlight, the pH will drop back down.

With your CYA level, wait for the FC level to drop below 10 ppm though technically even 23 ppm FC with 40 ppm CYA is equivalent to only 1.4 ppm FC with no CYA (i.e. typical of what may be found in indoor pools that don't have CYA).

Richard

[mohawk]

Here are my numbers:
PH-7.5
FC-5.0
CC-0
ALK-220
CYA-Not on 30 yet.
I just added the 3rd 1.5 lb container on CYA into the pool and the return jet is bubbling on top for the alkaline.

[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 (http://www.poolforum.com/pf2/showthread.php?t=191) 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? :confused:

[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.:confused:

[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. :D

Riles