Metals or Algea?- Please Help

[Armytiger]

I apologize that this is long but I wanted to give you the complete history. I have been fighting metal stains/algea for a couple of weeks and need some advice.

Approximately two weeks ago I noticed that my pool steps were turning brown and would not scrub off. The clerk at Leslie's reccomended rubbing a Vitamin C tablet to see if it was metals and it was. I brought the CL levels to 0 threw in the expensive stain remover from Leslie's, (which I now know how to buy much cheaper thanks to this forum), and followed it with metal free and Leslie's Algea Prevneter (is this the same as polquat; never heard of polyquat before reading this forum). Ran the pump for 24 hrs then back washed. Waited a couple of days then started to introduce chlorine (trichlor tablets via inline chlorinator) slowly. Everything worked beautifully until a couple of days later the water turned green with what appeared to be algea. At this point I went back to Leslie's and was advised that it was ok to shock the pool, which I hesitantly did despite reading mbar's instructions since Memorial day weekend was quickly appraoching. Mustard stains returned and pool was a brownish green with what appeared to be both algea and metal stains. I decided to put an abundant amount of shock (almost 3 pounds of chlorbrite) in the pool to kill the algea and shut off my chlorinator to bring the chlorine levels down before repeating the Vitamin C treatment. I noticed over the next couple of days that as my ph dropped the pool started to become crystal clear to the point where the mustard stains completely disappeared without having to repeat my treatment. I also noticed that when I tested my water I was not showing any free CL. I went back to Leslies to verify my CL which they did.

I was a little befuddled as to why I did not have any CL in the pool and realized that I had forgotten to turn the chlorinator back on when the pool cleared up. Fearing that I may get algea back in the pool and thinking that my metal problems were behind me I put the chlorinator on 5 and threw in a pound of shock shortly after a nice afternoon rain storm and noticed within 30 minutes that my water was green again.

I am assuming that for the water to go from clear to green in half hour that it has to be metals is this correct? With this assumption I have turned my chlorinator off and running my filter 24/7 hoping that when the cl levels appraoch zero again the pool will clear up. Once the pool clears up I plan to backwash even though my dp has only risen a couple of psi. Is this correct? Assuming the metals do clear up how do I get rid of them? Do I need to add more Metal Free. When can I start to put CL back into the pool?

Here are the stats prior to adding shock and turning the chlorinator on for 1/2 hour:

27,000 gallons
lined inground
city water

FAC 0
pH 7.5
Alkalinity 90
Ca 50
CYA 30
phosphates 200

[CarlD]

It's POSSIBLE you have metals since Vit C worked. OTOH, what Leslies did NOT tell you is that Polyquat in large amounts drives FC to 0. When I close in the fall I shock to the appropriate level, then I dump in a quart of Polyquat. In 48 hours, my FC is zero and I then shock to to the approriate level (based on CYA level) and close.

I'm GUESSING you have algae and you need to shock up to 15 and hold it there. Others may say "wait a minute--the clues for metal are too great." I'll concede to their superior knowledge, if so.

Carl

[Armytiger]

UPDATE: I ran the filter through the night and the water is clear with a slight hint of a "greenish brown" discoloration. I tested the water using a DPD test kit. (I'll be upgrading to a FAS-DPD soon) and my pH is still around 7.5 and cl is low. What is my next step? I know that I need to add cl should I use an inline chlorinator or should I drop a couple of 3" tablets in the skimmer? Based on the discholoration that I saw yesterday do I need to add another dose of metal free before adding cl? I've noticed a couple of small areas of algea forming on the walls as well. Should I sweep the pool and add an algea preventer? I have noticed that this site reccomends polyquat for algea prevention. Is polyquat a brand name or the base chemical that is in all agea preventers?

[CarlD]

Not sure I can answer all your questions...my knowledge of metals removing is limited.

PolyQuat is an ingredient used in SOME algaecides, but not all. It's better at preventing algae than killing it but is the best and only algaecide we recommend. It's all made by Buckman but it's sold under all kinds of names. I've seen it called Black Algaecide, Mustard Algae killer, etc.

But all you really need to care about is that the ONLY active ingredient is 60% poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio ) ethylene dichloride] , or, as I like to put it: Poly....<something unpronounceable>...

In large amounts it WILL drive your FC to 0 (like a quart in your pool), so be ready for that. It's better as a preventative, 1-2 oz/week.

Carl

[PoolDoc]

ArmyTiger,

You've got iron in your pool water. Your situation is very similar to this one
http://www.poolforum.com/pf2/showthr...5-I-m-Confused

Read it, and see if it makes sense. You can follow the same recipe. Post your results after a day or two. I'll try to notice, but if I don't remind me by email at poolforum AT gmail DOT com.

Ben

[Armytiger]

Ben,

I followed the steps in the post that you linked by adding one quart of bleach into the skimmer and a quart of "metal free". This is the second quart of "metal free" that I have put in the pool in the past 2 weeks. I put a dose of polyquat into the pool as well.

In the post that you linked you mentioned "There are EXACTLY TWO ways to remove iron from pool -- no more. First, you can get it into a form you can filter out (orange fluff), and then do that. Second, you can turn it into orange, brown, or black STAINS that are stuck to something. The inside of your filter is OK, the inside of the skimmer is not too bad, but the pool surface or your white swim suit is not so good."


Can you please elaborate on the two methods. I would prefer a method the forms a precipitate that I can either filter or vacuum out?


Thanks,

Dale