Water green, pool man says I need to change sand

Oct 23, 2015
7
mesa, az
I recently fired my pool man, as I had a hard time believing him. He claimed that, because my pool was replastered twice, that caused the sand to get clogged up and I need to replace the sand. Actually, he said I needed to replace my entire filter (five years old). Then he said my laterals are probably broken. Then he said I would need to replace my backwash valve (fixed with a couple of O rings).

So, I've decided to take matters into my own hands. I guess my first question is, should I replace the sand? Having read a number of posts here, it seems to me that green water is a chemistry problem, not a sand problem. What are the odds that the sand is the source of my green water?
 
Welcome to TFP!

Chances a filter causes green water, none

Chance you need to replace your sand, possible but doubtful. With the pump off take off the top of the filter and see what the sand looks/feels like. If it feels like sand and is fairy clean, no problems. If it feels like concrete, yea - you may need to replace it.

Laterals cracked? Why would he say that? Are you getting sand in the pool which is the common symptom of a cracked lateral.

You need two things, a test kit and liquid chlorine. I recommend the TF-100 from TFTestkits.net
 
Good move taking charge of your pool. :goodjob: As Tim said, the TF-100 is the way to go (link below). Great value fully-stocked with plenty of Taylor reagents. Ask for the speed stir too! Until you get the kit, stick to using regular liquid bleach as your sanitizer - generic is fine. Nothing else right now. Stay out of the pool store too. :) Your TF-100 test kit will tell you everything you need to know. Welcome!
 
Sand is usually never the problem. The saying goes, "The sand has been around for millions of years before it got in your filter. Do you really think a couple years in your filter changed the sand at all?" A thorough deep cleaning of the sand is usually all that's needed, if even that. Deep Cleaning a Sand Filter

Green water is always a chemical problem. A cloudy pool could be a filtration problem after all algae has been killed and you've passed an OCLT (overnight chlorine loss test).

Get that test kit on the way and while you're waiting for it to arrive. Start with ABCs of Pool Water Chemistry in Pool School and check out the links in my signature as well as others.

Tinker around with Pool Math as it is a marvelous tool and is essential when dealing with chemistry issues and proper dosing of chemicals during a SLAM procedure.

Welcome to TFP! :wave:
 
So mad! Pool man came by for the last time. He's sticking to his theory that I need to change at least the sand, preferably the whole filter. Pretty sure he's completely full of ca-ca (and I don't mean calcium ;) ). I told him about the CYA level being 90-100. He didn't really have a good reason for it, but before he left, he had replaced the tablets in the floater. I thought I read somewhere on here that those tablets have CYA as well as chlorine.

Have I been completely scammed by this guy for the last nine months?
 
Discontinue the tabs and switch to liquid chlorine either from the pool section or liquid bleach. If you get bleach only use 8.25% unscented, and not the splashless variety.
 

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So mad! Pool man came by for the last time. He's sticking to his theory that I need to change at least the sand, preferably the whole filter. Pretty sure he's completely full of ca-ca (and I don't mean calcium ;) ). I told him about the CYA level being 90-100. He didn't really have a good reason for it, but before he left, he had replaced the tablets in the floater. I thought I read somewhere on here that those tablets have CYA as well as chlorine.

Have I been completely scammed by this guy for the last nine months?
Welcome to the forum.

How do you know what your CYA level is? Pool $tore results? Unfortunately pool store results are usually not accurate at all, and you need to get one of the recommended test kits.

Test Kits Compared

I recommend the TF-100 from TFtestkits.net with the XL option. The Taylor K-2006 (which I own) just doesn't have enough reagents, especially if a SLAM is needed to eliminate algae.

When using 3" Trichlor tablets, for every 10ppm of FC added, you are also adding 6ppm CYA.

If your CYA is indeed 100ppm you will need a daily (clear water) FC minimum level of 7ppm, with a target level of 12ppm, and your SLAM FC level would need to be maintained at 38ppm.

If that CYA level is correct you will need to consider a large amount of water exchanges to get that CYA down to a reasonable level.

Chlorine/CYA Chart

As mentioned, stop using chlorine tablets. All you need is liquid chlorine, aka bleach.

How to chlorinate your pool

Until you get a reliable test kit it will be next to impossible to address your water issues. In the meantime you can add one large jug (96oz) of 8.25% laundry bleach daily to try to keep things from getting worse. This will result in about 5ppm of FC added with each jug.

Also be sure to read up on How to SLAM your pool to eliminate the algae.

Be sure to read through all the articles in Pool School to prepare yourself to properly maintain your pool.

While it may seem overwhelming at first, once you start TFPC you will be amazed at how simple it is to maintain a sparkling clear pool.

Dom
 
Although not impossible, I cant image you need to replace the sand, I had mine replaced after 18+ years and that was before I found TFP- most likely just needed a deep clean?


No, but you'll probably spend significantly less maintaining your pool by yourself, and it will remain crystal clear.

Off the top of my head, my 18,000 gallons cost around $300 (max) in chlorine to keep it open for 5 months this year. Never had a pool guy so I don't know how that compares.
This is about the same I spent in total for all Chem's & regents, with our 5 month season. Used just Bleach/liquid chlorine and a few jug's of MA. I'm getting a 2 year life span for the TF-100 Test kit, with about $20 for extra regents. So that's less than $50 a year for true testing that I find is cheap for all that is saves me both in $'s and grief.
Plus i feel like a kid every time i use the Speedstir:D
 
Just wanted to thank everyone for all of your help. I feel so lucky to have found you guys. I've been SLAMming my pool for five days now, and the water is no longer green! Been running my pump pretty much 24/7 and back washing every day. While the water is blue, it's still pretty cloudy. Any thoughts?
 
Just wanted to thank everyone for all of your help. I feel so lucky to have found you guys. I've been SLAMming my pool for five days now, and the water is no longer green! Been running my pump pretty much 24/7 and back washing every day. While the water is blue, it's still pretty cloudy. Any thoughts?
I'm with the last two posters, do you have a proper test kit? Without one you can not properly do an OCLT, which passing is one of the three requirements to complete a SLAM.

If you guess your way through this you could end up stopping too early, and wind up with another algae bloom, wasting all the $$ you spent in chlorine for the SLAM.

How do you know that you are maintaining the proper FC level? How are you checking for CC's?

Don't backwash the filter until you have a 20-25% rise as mentioned. A slightly dirty sand filter will filter better than a squeaky clean one.

Dom
 
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