On the right track with Algae Problem?

[darrenfauth]

Hi,

Pool noob that is getting a pool with the purchase of foreclosed house. Pool specs are in my signature.

Pool was dark, swampy green with no knowledge of how long it had been that way. Bank had the pool drained and let it sit that way (in hot Texas sun) for about 5 days They say it was acid washed. Pool was refilled and still had large dark algae stains about 1' below the water around most of the pool.

Week later the pool was swamp green again. Seems they came out and put liquid chlorine in because 2 hours later it was clear (although stains remain).

We are close to closing on this house and I am trying to get a handle on the pool issues. I've dealt with Leslie's Pool. I've used about 7 packs of Super Shock and 1 pack of water conditioner over the course of 3 weeks. Floating 3" Jumbo Tabs in the floaters.

I run the filter non-stop. I leave the Polaris running most days. I've backwashed the filter several times when the PSI rises from 5psi to around 12psi (which greatly helps the circulation). I continue to scrub the walls with a vinyl/metal brush. I just started using a leaf bagger on the bottom (although I currently can't see what I'm doing...too cloudy).

The algae spots had also grown and were slimy to the touch. That's when I learned about the BBB method here last night and promptly put 9 Gallon jugs of Walmart Great Value Bleach (6%) in last night. My current test kit (to soon be replaced with the TFP one) is a basic Chlorine/PH kit. It only tests Chlorine up to 5ppm. My PH tested at 7.4.

I took a water sample to Leslie's to get all my readings to post here. He said 'he couldn't read above 5ppm and I should bring it down.' I said 'But, don't I need to have my chlorine level high to kill the algae?' He said, 'No...some algae thrives on high chlorine.'

I went in thinking I needed to keep my FC in the 20ppm range for a few days to hopefully get rid of these dark algae stains on the side and get the pool under control. Well, I don't trust Leslie's anymore to guide me in the right direction (without just trying to sell me something) and vowed to never return! :-D

Right now the water is white/blue cloudy and I can still smell the chlorine from the bleach.

I'll get my readings up ASAP...but in the meantime wonder: 1) Am I on the right track with wanting to keep my FC level at the 20ppm level? 2) Will these black stains on the side ever come off?

 

[ktdave]

' He said, 'No...some algae thrives on high chlorine.'

That's one of the most rediculous things I've heard a pool store person say!

To get the best advice we need your Cyanuric Acid (CYA or stabilizer) level. If your CYA is less than 50, 20 ppm chlorine is good. Keep that free chlorine (FC) level until it holds overnight, meanwhile run pump 24/7, brush, and vacuum, and backwash the filter as necessary.

Welcome, we will answer all your ?s

I'm not experienced with stains.

 

[JohnT]

I think you're on the right track. You can go to 25ppm with a gunite pool. Test it by diluting your pool water sample with 4 parts distilled water, then testing the mixture. Multiply the reading by 5 to get the real answer. A key thing is that you need to test and add more chlorine really often. Every 4 hours is best, every 8 hours is tolerable. The high chlorine may help with the stains if they are organic. Frequent brushing is good in an algae fight, although it may make the pool look worse by stirring up the crud on the bottom.

One thing you are missing is your CYA level. If the pool was refilled, it may be low, but if it is too high it can predispose you to algae again.

Milky blue is a very good sign. Stick with it and the water will be clearing up soon.

Dave's kit at TFtestkits.com (or is it tftestkit.com?) is great.

 

[The Mermaid Queen]

You are indeed on the right track. Many many pool store employees do not have a clue, as you have learned!

It sounds like you have large-ish debris in your water?? you need to scoop all of that out, even if you are scooping blind! That stuff will use up your chlorine and there will be less to kill the algae. Also keep up the brushing and backwashing. All of this will help you clear your water faster.

As for the black stains, that is not my forte. If the pool was indeed acid-washed, I would think any staining would have been removed...

Keep your FC up until it will stay up overnight. Use the dilution method JohnT referred to for testing your FC. This method is only good as a stop-gap, and is better than guessing. Get that test kit asap. Test as often as you can, and add bleach to get it back up to 20 or 25.

Some helpful links are in my signature, especially the stickies, and Jason's calculator.

Welcome to TFP!!

 

[darrenfauth]

Thanks for the quick replies!

KTDave...that's what I thought. Felt like he was trying to create an illusion of reliance on them for telling me what I needed..which ultimately includes buying their chemicals.

JohnT...thanks! I guess I see now how my max 5ppm kit can actually be used to read up to 25ppm...through the dilution, right? Cool. Just to be clear..that's 1 part pool water + 4 parts distilled water. Right? If I get a reading of 4...then I know I'm at 20ppm.

I'm still hoping from some of the pics I've seen here that the stains can actually disappear. Cause right now, the suckers won't even budge with the scrub brush and all the muscle I can muster.

 

[JohnT]

JohnT...thanks! I guess I see now how my max 5ppm kit can actually be used to read up to 25ppm...through the dilution, right? Cool. Just to be clear..that's 1 part pool water + 4 parts distilled water. Right? If I get a reading of 4...then I know I'm at 20ppm.

Exactly. You can use a tablespoon, a shot glass or whatever you want. The accuracy suffers some, but it's close enough for what you are doing.

One thing to keep in mind is that high chlorine can skew your pH test, so don't trust your pH reading completely during the cleanup.

 

[darrenfauth]

MQueen...we were typing at the same time. Thanks for the encouragement, info and links as well. Yes, I'm finding that the bottom has quite a few leaves that have settled there. They are coming up with the leaf bagger and Polaris. As for the acid wash...I doubt the quality of the work being done by the bank's 'pool guy'.

JohnT...will do and duly noted on the PH, thanks again.

Here's a pic of the side of the pool.