Yellow Algae or Pollen

[Lroberts32]

We are having problems with our pool having a yellowish brown film around certain areas of the pool and puddling dust on the pool floor. We live in Illinois and are around wheat and corn fields and many pine and oaks trees too. At first I thought it was metals in the water because we fill from a well but use a metal sequesterant. I ordered a metal test kit and copper is 0.3 which doesn't seem high. My pool store thought it was pollen and rust from the grass. This makes sense because when walking in the yard my shoes get covered with orange/brown dust.

With this theory we used DE in our sand filter and a skimmer sock and spent alot of time vacuuming and brushing for over a week. It did clear up and in time for a long 4-day weekend with heavy pool usage. Water was crystal clear and no dust or yellow film.

After the heavy usage we shocked the pool. All seemed fine. Alittle green tint but not much. Seems like our white liner has a bit of a brown stain on it so the coloring of the water isn't exact.

After a week we had another weekend of heavy use and then a rain storm of 2-3 inches of rain. We were glad to have this rain for the pool so we didn't have to fill the pool with well water. BUT...now the yellow and brown film is back and the the water clouded up and it's greenish colored and there's dust on the floor again.

Is there a way to tell if this is algae or pollen? And what can I do about it? Do we put in algaecide? Do we shock more? Oh I forgot to mention our phosphate level is high (over 1000).

Current numbers are:

cal har 260
tc-8
fc-12
PH 7.4
alk 180
cya 160

Appreciate any insight...thanks !

 

[YippeeSkippy]

Its too late to see pollen usually. If you're seeing green you need to do a SLAM procedure (find directions under the Pool School tab). You mention you "shocked" the pool, but how and with what? A SLAM is more than a one time dose of chemicals because algae can survive and reproduce if the chlorine level is too low and too short a duration.

Do you use one of the two recommended test kits (Taylor's K-2006 or TF-100 both avail via TFTestkits.net )?

 

[Swampwoman]

Good morning, lroberts!

I couldn't tell whether you've adopted TFP methods or not, but since you've been on the boards this summer, forgive me if my observations are redundant.

With cya of 160 ( which I assume you've diluted to calculate) you will have a very difficult time successfully SLAMming to TFP standard.

You really need to do a series of partial water changes in order to bring your cya down to a manageable level. Preferably 30 for slam purposes. I did just a quick glance of your other posts, and noticed on opening that you had cya over 100 then too.

CYA level is critical not only for a successful slam, but also for preventing the need to slam and maintaining adequate sanitation. Please review the chlorine:cya link that's in my signature.

Secondly, .3 ppm copper is in fact a high enough level to cause staining of water tint when the ph is high or when slamming. Its just on the wedge, but by doing a partial water change, you would also be able to lower it unless you have copper in your well water. I'm guessing your use of Algaecides etc. might exacerbate the level from the well.

Thirdly, on well water, have you tested for iron? My hunch is that's where the brownish staining on the liner is coming from.

I am on well and appreciate any concerns you might have re water changes...because you need to sequester again at lower chlorine before doing anything else

BUT I also think its wisest for those on well to try to avoid completely the need for slamming at all (to avoid oxidizing metals..,even with sequestrant, its imprecise!) -- so that's why I'm suggesting you take the time now to get your cya down to a manageable level through a series of partial water changes and sequestrant refreshing before you entertain a slam.

Lastly, can you post a pic? After sorting out your cya, it would be good to do the overnight chlorine loss test (see link in sig re slamming) to tell if you still need to slam, but its also possible these colors could be coming from a combo of metals and enviro dirt...though its more likely algae because at very high cya it is just TOO hard to maintain the effective "kill ratio" between FC and cya.

Hope that gives you a way forward!

- - - Updated - - -

Ps...like me, you have a vinyl liner. Please note that when doing water changes never to let the water drop below a foot in the shallow end. If you have a high water table, do even smaller changes, refill, then dilute again. That will keep the liner from floating, wrinkling etc.

 

[domct203]

............
cal har 260
tc-8
fc-12
PH 7.4
alk 180
cya 160

Appreciate any insight...thanks !

Are these your own test results, or are they from a pool store?

Your chlorine readings don't make sense, FC can't be higher than TC, which is the sum of FC + CC.

Dom