Hello from Ohio!

[gojiro]

Hi! Long-time browser who finally wised up and joined this awesome website!

I bought my house a year ago. Never owned a pool before, but the previous owner said it wasn't very difficult to maintain the pool and hot tub. HA! I've had nothing but trouble with both.

My current problem, which I was mystified about until I came here, is that I keep getting "crud" -- a fine, powdery accumulation on the bottom of the pool that brushes up easily into a cloud. Sometimes it's gray, sometimes light brown, sometimes a light green. We had problems at the beginning of the season with maintaining the FC levels, and ended up dumping 11 pounds of shock over 24 hours (6 in the evening and 5 the next morning) on the advice of the pool store guy. That seemed to do the trick, but the crud still appears regularly. I'm brushing the pool every day at this point, and it comes back as bad or worse within 24 hours.

After reading the Pool School article, I suspected my CYA was too high. Sure enough, it tested out at around 90 or 100. So it looks like the crud is probably dead algae? I haven't seen any live algae, save for a small spot in the skimmer door early in the summer, which hasn't grown back after we scrubbed it off and added algaecide.

FYI, the pH is currently at 7.6, the Cl is at 5.0 (we shocked 5 days ago), and the TA is around 80.

The water is usually crystal clear, but becomes a little cloudy after brushing up the crud.

I plan to dump some of the water and refill this weekend to get the CYA level down. Any idea how much water I need to dump? Half the pool? Less? More?

Oh, also, the liner is tinted pale green in spots -- mostly along the underwater rim around the deep end. I'm guessing this is from the copper in the algaecide, as it is definitely not algae and doesn't scrub off. Any idea how to get rid of it?

Thanks in advance for your help. This site is awesome, and my just save my sanity! Not to mention my wallet!

Dave

 

[polyvue]

I plan to dump some of the water and refill this weekend to get the CYA level down. Any idea how much water I need to dump?

Welcome to the forum --from another new participant!

My advice is limited to water dumping since I don't have expertise with algae control or removal. Twice a year I pump (to waste: storm drain) about 15% of pool water. That's about 9" below mid-tile in my pool. This effort slightly reduces Total Dissolved Solids (including salt), CYA and total chlorine. Alkalinity and calcium are unchanged because they are nearly the same ppm in the make-up water (city supply.)

In your case, you might want to drain off much more. If you need to cut CYA in half, for instance, a 50% drain and fill is a good solution. Not sure what this will do for your debris problem, however.

 

[Bama Rambler]

I don't know what your water table is like in Ohio but you need to drain and refill till you get your CYA to about 50ppm. You can do that by draining 50% at once if your water table is not an issue or you can do it through several partial drain and refills.

I recommend doing this first because if I remember correctly if you raise your FC level high enough for a CYA level that high the staining will get worse. I'm sure someone will correct me if I'm wrong about that.

What are you using to chlorinate your pool? If it's pucks you'll be right back in the same situation before long with the over-stabilization. I'd recommend switching to bleach or liquid chlorine. (yeah, I know it's the same thing)

The draining will help the copper levels a little too if that's what the Algaecide had in it. Do you remember what it was that you used?

If you don't have one of the recommended test kits, you should consider getting one.
It wouldn't hurt to test your fill water too.

 

[gojiro]

Well, that's just logical, isn't it. :-D

The algaecide was the local pool store's brand and was just called Algaecide-60, I think (I'm at work, so I don't have the bottle in front of me).

I do use the tri-chlor tablets in a feeder, and powder shock. I'll be switching to the BBB system, though. I think the reason the CYA is so high is because I added some at the beginning of the season, when we couldn't hold our FC level. Obviously, I had no clue what I was doing.

Thanks for the advice, folks!

 

[Bama Rambler]

You may have gotten lucky. I did a little searching and it appears that that algaecide is polyquat 60, which is what is recommended here. NO copper !

I'd still have the water tested for iron and copper just to be sure there's not any in your water already.

 

[gojiro]

Thanks for checking! If that's the case, however, what would be turning my liner green? Any idea?

 

[Bama Rambler]

Just because the algaecide didn't add any doesn't mean it's not there. That's why I suggested taking a sample of you pool water to the pool store and have it tested for metals. What you're seeing could be algae. The problem with algaecide is that it's not a one time thing. You have to keep adding it weekly unless you get your FC to target level and keep it there.

Once you get your CYA down, Shock the algae out it and keep your FC up, you're gonna have a much happier pool. You amy even see those "stains" go away.