Having trouble with green water

Babybaits

Member
Jul 27, 2023
8
New York
This is the first time I'm dealing with a pool, so please bear with me. Everything has been going good except when I had to shock the pool 2 times because of algae. It's a 4000 gal pool, and according to what I read, it would need about 6-7 oz. for regular maintenance, but I could double or triple it if it's for algae, so I put in 1lb, and it worked beautifully within a couple to a few hours. I just had to deal with too much chlorine. Even after a few days, it was still 10+ so I just drained some water out and added fresh water. That worked.

Now, yesterday I realized the water was looking a little green but wasn't as bad as the other 2 times, so I only added around 6 oz of shock. This morning it was a little worse. Couldn't figure out why until I found out that my son never changed the filter last week like he was supposed to. I changed it but wasn't sure if I was supposed to add some more shock, so I waited a couple of hours. Nothing changed, so I added 6 oz more. A few hours go by and nothing. I even checked the chlorine level, and it was at 5, so I added another 6 oz. of shock. It's now several hours later, and it doesn't look like there's a difference. If by the morning there's no change, should I just add a pound of shock, or will that be way too much? I was trying so hard to get the pool ready again for the HOT day coming tomorrow.

What I'm curious about is if there's a difference with the way the shock affects the algae if you put in the correct amount all at once versus if you put it in half at one time, and then more later on?
 
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Hey BB and Welcome !!!

To expand on the above, you're new and don't even know what you don't even know yet. Don't worry, we ALL got here the exact same way. We never forgot how bad it sucked to get us here. :)

Except for the people finding us before/during their build. But they're reminded how it could have been on the daily when we get a handful of frustrated folks each day.

Read up so you can get an idea how it all works. Ask away and we'll happily guide you.
 
Maybe I should've elaborated a little more. Yes, this is my first year of doing this, but I'm not going blindly at the chemistry. Before even getting the pool I did a lot of reading. I know the basics of chlorine, ph, alkalinity, hardness, etc and the numbers they should be at and all those numbers have been perfectly fine.

It's now morning and I'm standing her still with a green pool and don't know what to do. I retested and all numbers are within range except for ph, which is a little high (which I read that could happen when you shock it) and the free chlorine, which is at 10+.
 
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Please don't take this the wrong way, but was that an answer to my questions?
Yes-
Please read through the links he posted to get a better understanding of the how’s & why’s of caring for your pool.
- going over slam level for your cya just risks damage to your liner, equipment, & swimmers & wastes chlorine.
- going under slam level for your cya really doesn’t do the trick.
Maintenance level (target) fc will prevent you from having an algae problem/unsanitary water in the first place but won’t solve the problem once you have it. You need the SLAM Process with liquid chlorine for that.
IMG_6554.jpeg

Its all about knowing where you stand with accurate testing Test Kits Compared, giving your pool what it needs when it needs it, nothing more nothing less, & knowing what effects each chemical you add will have on all the parameters.
Post your test results & we can help you.
Fc
Cc
Ph
Ta
Ch
CYA
 
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I must add that the recommendation to drain, scrub & start over is a valid one with chlorine being so expensive.
With a small pool that’s very green & an undersized filter it can take ALOT of chlorine & time to clear. Water is generally much cheaper.
Then you can start fresh quickly with the temporary pool guide posted above.
 

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I know the test strips are easy, but they require a lot of interpretation and that is one of the reasons, they are extremely inaccurate. The methods used here at TFPs uses results from a proper test kit to give you scientific answers to your problems. Without accurate information we cannot provide the proper diagnosis and advice. In many cases with inaccurate test results, any advice given could make your problems worse, and pool store testing is not much better than the test strips.

One piece of advice you were given was that with the size of the pool, the cost of chlorine would far exceed the cost of draining scrubbing and refilling with fresh water.

Here is an article on seasonal pools, your pool may be slightly larger, but a lot of the information still pertains.


For the most part, green water is algae, and chlorine prevents and kills algae. If you have algae in your pool, at some time, your chlorine level was too low for the CYA you have in your pool. It takes far less chlorine to prevent algae than to kill it once it is green. It sounds like the chlorine you are using is powdered, which contains CYA, so as you add powdered shock, you are increasing the CYA, which then requires more chlorine to achieve sanitation.

lc_chart.jpg
 
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You are getting lots of good info, but sometimes it can be a bit like drinking from a fire hose so I will try to hit the basics:

1. Here at TFP, your required chlorine level is a sliding scale based on your CYA level. This is different than what you are going to read most places who are stuck in 50 year old thinking that FC should just be 1-3.
2. Green = Algae and all algae is caused by low chlorine. Filters don't kill algae.
3. TFP teaches people to only add the chemicals your pool needs and trust your own testing. Pool stores, pool guys, etc. do not have good testing and ultimately their motive is to sell you stuff.
4. #3 typically involves purchasing a $100+ test kit to hit all of the correct numbers, but since your pool is smaller we can simplify it a lot for you if you can easily drain and refill. Read up on the Seasonal/Temporary pool article posted above and see if that will work for you.

Welcome!
 
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The stabilizer went from 50 (this whole time) to 100, although on the strip, it's lighter that what it says it is.



View attachment 517856
Even if the strips were accurate (they’re usually not & are easily skewed by higher fc levels) the ranges they show are simply too broad for proper water management.
For cya you need to know your actual level within 10ppm to chlorinate properly as you can see by the FC/CYA Levels chart provided.
To do the SLAM Process you must have a Taylor k2006c or tf100 - as they are the only ones contain the necessary fas/dpd tests & cya test/reagents you need.
The slam process is easier to do at lower cya levels (30/40ppm) so if your cya is really that high you’ll need to replace most of the water anyway.
If you just wanna drain, scrub, & start over then go with a kit like the hth 6way (currently $20 at lowes) & follow the temporary pool guide to prevent this from happening again. You can always add the fas/dpd kit or upgrade your kit later.
 
I landed up adding 14 oz of shock and it did the trick. Chlorine and ph were high so I drained some of the water, added fresh water, tested the levels (yes, with a strip) and things are back to normal.

I do have to say that I came on here and asked 2 questions. (1)Should I add more shock and (2) is there a difference whether you put in the correct amount of shock all at once versus if you put it in little by little. I didn't get an answer to either of those questions. All I got were links to read up on things assuming I haven't done that already (not by everyone). Some might as well have said "go figure out the answer yourself". At least 1 person suggested I drain my pool, clean it and refill with fresh water, saying that would be cheaper. If I would do that, it would take about another 2 to 3 weeks to fill it. I have a well and I'm not using all the water and taking a chance of damaging my well pump. To get water delivered it would cost about $500. Shock costs $30 and I still have plenty of chlorine tabs. Another forum I posted on, people actually gave me answers so I'll stick with that forum.
 
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I do have to say that I came on here and asked 2 questions. (1)Should I add more shock
Not until you know your actual cya level- until then you should add 5ppm each day to keep things from getting worse
(2) is there a difference whether you put in the correct amount of shock all at once versus if you put it in little by little. I didn't get an answer to either of those questions.
Yes- you need to MAINTAIN shock/slam level fc for your cya as shown in the chart & here FC/CYA Levels to get a leg up on the algae & kill it faster than it proliferates. As I mentioned too little doesn’t cut it & too much risks damage to your liner, equipment & swimmers & also wastes chlorine.
Regular Maintenance (target) fc levels aren’t enough.

I am sorry you don’t feel you’ve received helpful advice but we don’t want to lead you astray with inaccurate advice based on what your strips say or just blindly telling you to throw in stuff.

you haven’t ever told us what type of chlorine “shock” you’re using so it’s hard to know how it will affect your water depending upon the amount you use.
PoolMath will tell you what slam/shock level is based on your cya.
 
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I didn't get an answer to either of those questions. All I got were links to read up on things assuming I haven't done that alread
Because we don't do it your way and we are not asking you how *you* do it. You are asking us about our way. You don't need to do things our way, we simply cannot help you with the other ways, and everything you've done or asked is all other ways.

If you had read all up on our way as you said, you'd know we don't put any faith in test strips and fear causing harm to someone's pool if we give directions from them.

We wish you the best. If you'd ever like to try our way, we'd be happy to show you how. :)
 
+1 what newdude said.

Over and over, argumentative folks come on to this site solely for the argument............that's not us.

TFP procedures and methods are what we teach........simply because they work. The folks who need to have the argument need to find another forum to do so.
 
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I landed up adding 14 oz of shock and it did the trick. Chlorine and ph were high so I drained some of the water, added fresh water, tested the levels (yes, with a strip) and things are back to normal.

I do have to say that I came on here and asked 2 questions. (1)Should I add more shock and (2) is there a difference whether you put in the correct amount of shock all at once versus if you put it in little by little. I didn't get an answer to either of those questions. All I got were links to read up on things assuming I haven't done that already (not by everyone). Some might as well have said "go figure out the answer yourself". At least 1 person suggested I drain my pool, clean it and refill with fresh water, saying that would be cheaper. If I would do that, it would take about another 2 to 3 weeks to fill it. I have a well and I'm not using all the water and taking a chance of damaging my well pump. To get water delivered it would cost about $500. Shock costs $30 and I still have plenty of chlorine tabs. Another forum I posted on, people actually gave me answers so I'll stick with that forum.
Your right, we didn't answer your question, but we did provide you with basic information and resources, because that's what we do. Our aim is to inform and teach so the you can "go figure out the answer yourself". One of the goals of this site is to teach, so that eventually, you don't need to post questions and you can pay it back, by answering questions.

Scientific testing is needed to provide scientific answers. If guess strips work for you, fine, continue to use them, and I wish you good luck.
 
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