Hello from Montreal!

Greetings!

My name is Nick, I'm from Montreal. I just moved in a house (bought) in late fall; so I became the owner of an older vinyl in-ground pool. The specs are

Roughly 12-13K gallons (50,000 liters)
HP Pump
Sand filter
No salt or chlorinatore; using a floating dispenser.

I'm a true newbie at pool maintenance, although I've begun educating myself by reading several threads here and at other websites, as well as having chats and analysis done at pool store (which has not always been useful). So I'm learning the ropes, and this website has been the most useful I would say!

Pool was recently opened (late may); unfortunately, the pool has been closed very early in fall last year, so there is a lot of algae in there. Green water, 12-18 inch visibility max.. pH was at 7.3 yesterday, some Alk again to push it in the 7.5 zone...
I'm chlorinating w/ the floater but after reading more, I've begun agressively "shocking" the pool. Yesterday night, I shocked w/ 2 pounds of calcium hypochlorite (50% chlorine avail. approx), and a few hours later, I've emptied a full gallon of sodium hypochlorite/bleach (10% chlorine), most agressive shock so far. Backwashing whenever the pressure gets up 5-6 psi+, almost every other day so far, water coming out is pretty green for about 60+ secs or so...

Despite latest shock, no improvements yet in water appearance... same visibility this morning. Will keep at it!! THis thread will be my way of keeping my moral up :)

2 initial questions for you:

1) should I keep adding sod. hypochlorite during daytime? My understanding is that a lot will be lost to sunlight, so I was thinking about shocking every day at sunset, with 1-2 gallons of sod. hypochlorite and keep fighting the algae

2) any use adding algaecide for this battle? I've tried it initially after shocking the pool, following the store's recommendation.. but it didn't achieve anything in appearance. My understanding at this point, from reading various threads, is that algaecide won't be much help at this point and that the battle will be won with aggressive daily chlorine shocks... Probably throwing $ down the drain at this point with algaecide, but I could be wrong?

I'll defeat my green enemy eventually!! :)

Cheers and thanks,

Nick

Hello Nick, welcome to the Pool Forum.

May we please ask you to complete the

Pool Chart Entry Form
Pool Chart Results

That gives us the info about your pool all in one place.

Your vinyl pool doesn't need calcium so you can use plain bleach to shock, or use dichlor granular shock. The latter will also add CYA (stabilizer) which you do need and should bring to around 50 ppm. The floater you're using will also add CYA.

How are you presently testing your water?

Dichlor and trichlor will drop the pH a little. You said you added 'Alk' to raise the pH. What, specifically, is Alk.? Can you get 20 Mule Team Borax, or Washing Soda? Zeller's or Loblaw's might carry those products. Borax will raise the pH nicely, Washing Soda will also raise the alkalinity some.

Keep adding the 10% bleach and yes, your instincts are correct: add it at night to avoid losing it to UV light. Although, if your weather is like what we had in Ottawa over the weekend, there's not much sun to break down the chlorine right now. Add the chlorine until the water isn't green anymore, or–if you have a good test kit–until your overnight chlorine loss is less than 1 ppm.

Don't put in any algaecide just now. The high chlorine level will destroy it. Spend the money on bleach, instead. Keep the pump and filter running, backwash/rinse as needed.

We'll help you defeat the Green Monster :)

Thanks Anna! I've filled out the Pool Chart Entry form with the appropriate info

Interestingly enough, there is no mention on the bottle of Alk (Eco-Alk?) on the chemical that is included... Didn't know this was legal for a company not to include the ingredient list, but apparently it is! Possibly Borax labelled another way to sell for a higher margin at the pool store :) ... Either way, it seemed to work fine. My pH has raised to 7.4 and Alcalinity is in the 90+ range, so all is good on that side.

My testing is very basic. I'm using the Red and Yellow drops (Phenol), which will give me some idea of pH and Chlorine... I also often bring a sample at pool store, but the folks there haven't been very thorough in their analysis I find... essentially they test pH and Cl also. No idea on my CYA level. It should be fine because the Chlorine level seem to hold up well... although I would love to have it tested because I'm wondering if it could be too high? (which would lower the impact of Chlorine). I haven't added any stabilizer deliberately, aside from the chlorine tablets in the floater

The kid at the pool store freaked out when I told him the shock treatment I did yesterday (1 gallon of bleach 10% + 2 pounds of calcium hypochlorite at about 50% Cl.), he said it was too much for a shock. I think he might be mistaken based on what I read here from all the folks with field experience w/ strong algae presence :) Then again, he's the same guy who told me to stop shock treatments w/ chlorine for a few days and go with 40% algaecide.... (!)

Will drop another gallon of bleach 10% tonight, hoping this shock will help. I don't dare go with 2 or 3 gallons yet since I don't have clear visibility on my Cl levels.... my testing kit is to basic to read high levels and really follow the evolution..

Thank you for completing the form.

Yes, you really do need a good test kit. I'm afraid I don't know what's available in Canada. You've probably seen in other threads that we suggest the Taylor K-2006. You can make your phenol kit read levels higher than 3 ppm by using the Shotglass Method. It's not highly accurate but it'll do on a very temporary basis. You do need to know what the CYA level is because it determines your FC target levels for shocking as well as normal maintenance. You may be able to buy a CYA test kit at your pool store and I do know Amazon carries it: Blue Devil is the brand name.

I looked up Eco-Alk. They don't say on the Website what's in it, either, despite their assurances of transparency of information. Since it raised both the alkalinity and the pH it likely is soda ash (washing soda).

There is a test kit link in my signature block; it leads to the test kits on amazon.com. Take a look and see what might be available to you. Let us know if we can be of assistance in your endeavours to beat the Green Monster.

Thanks again Anna!

I've purchased another test kit from a local pool store (Club Piscine Super Fitness); it's the Aquachek strip test. I know strip tests are a bit limited, but I couldn't find the Taylor K-2006 or more interesting kits so far (might order one online eventually).

In the meantime, the Aquachek has allowed me to validate a few things, including CYA:

This is today, sunny at 3PM... last shock was yesterday night.

pH: 7.4 approx
Free Chlorine: over 10ppm.. dunno by how much. I validated with a drop test and it's also saying over 10ppm total chlorine (not free chlorine)... so Cl level is still high despite sunlight
Alkalinity: in the 80 - 120 range
CYA: in the 30-50 range... from the color, I would assume that it's closer to 30 than 50.

So all is looking good on the chem side.

Appearance is still green, but I do feel there is some improvement (subjective)... The look is slightly more milky and a bit less green I find, and visibility might be close to 20-24 inches now despite the cloudy/milky. I know that the milky look can be attributed to dead algae, which would indicate that the battle is making casualties (Good!)

Still have a lot of work ahead of myself I think though, so I'm not taking anything for granted. I'm doing the best I can to brush the bottom and sides of the pool to help chlorine attack the algae. However, I can't really vacuum or reach debris at the deepest end of the pool because visibility is absolutely nil there and I have no idea the size and amount of debris there (shouldn't be that bad since I use a winter cover, but who knows).

The plan is to launch a surprise Bleach attack tonight, with 2,5 gallons (about 10 liters)... maybe even 3 gallons.

You know our opinion of test strips so I won't go into that here.

Your target shock level for 30 ppm CYA is 15 ppm FC constantly. Could be you have that, could be much higher, could be 10.5. Without a reliable way of testing higher chlorine concentrations you're just guessing, Nick. Then again, with the test strips you're guessing at the CYA as well so, in reality, we're just dosing the pool with a lot of hope.

Can you reach the bottom of the deep end with a leaf net on a telepole? Even if you can't see what you're doing you might be able to pick up some larger debris, leaves and sticks and such, if you think that's what's down there. Maybe nothing, given the winter cover.

My best suggestion is to keep adding bleach. And check into an online vendor who sells Taylor products in Canada.

You're totally right Anna; my testing kits limitations force me to "guesstimate" the current chem levels. Thankfully, with 2 different test kits (drops and strips), + occasional pool store tests + visual inspection of the pool, I think I'm operating on a bit of information, although it is indeed a lot of guesswork (and hope!!). I would love to have a sophisticated kit, and will certainly look to acquire one this summer. Can't believe how many pool owners and even some pool stores are using almost pre-historic testing!

I am happy to report that there was a LOT of improvement overnight, after the latest agressive shock treatment, with the addition of 4 gallons of bleach (10% active chlorine). The water has turned from green to pretty almost turquoise overnight!! Very encouraging. Visibility has improved to almost 3-4 feet, although the water is still blurry/cloudy of course. I now have a cloudy but turquoise pool, with almost to remnants of shades of green in the background. THe battle ain't over, but the green monster has become a turquoise wounded beast and it is definitely retreating.

Latest tests show that Chlorine levels are holding up definitely over 12ppm here at noon in full sunlight (dunno by how much over 12ppm... again testing limitations... but from the look of things, it is above 15ppm)

I am short on time today, but I believe I will be able to be much more effective on the cleanup job in the next few days and over the weekend, since visibility has improved and will keep improving hopefully. There doesn't seem to be that much debris after all, from the look of things, although the deep end (over 8' deep) is not clear enough to be 100% sure. Filter is doing well, backwashing every other day at this point (whenever it raises by 4-5 PSI)

We're moving on to phase 2 of the battle. Now I want to eliminate the "cloudiness" and improve true visibility. I am assuming that close monitoring of essential chem values (pH and Cl, as well as keeping an eye on CYA) will be key, as well as maintaining strong Free Cl levels (well above the 10ppm mark)...... and eventually the cloudiness will subside?

I am not yet considering adding algaecide, as you've made the point that it might be wasted on such high chlorine levels anyways.. and besides, Chlorine remains one of the best algaecide. I'll save the algaecide I have for maintenance and prevention of recurrence.

Cheers and thanks again for the support!!

Sounds good! Keep the chlorine at shock level until your overnight chlorine loss is less than 1 ppm, and that'll be tricky to do since you don't have a way of testing accurately. Going from cloudy to clear means filtering and more filtering. Once the FC level passes the overnight test you can let FC drop to the appropriate target for the CYA level and maintain that FC target.

Quote:

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Originally Posted by nick182

You're totally right Anna; my testing kits limitations force me to "guesstimate" the current chem levels.

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The test kit info page in my sig has links to a Canadian company selling the K-2006 -- though at this point you may only need the supplemental K-1515

Day 5= the battle against visible Algae Monster is now pretty much won! Water is clear blue, visibility is good, seeing easily the details in 4 foot depth and seeing relatively clearly even in the deepest spots. A little bit of blurriness in deeper waters still remains, but this pool can no longer be considered "cloudy". I could vacuum efficiently for the first time (vacuum to waste of course).

So in all, it took approximately 1 week and half from pool opening to get things under control, but I wasn't agressive with the filtering and BBB from the get go. I did invest a few days mostly stabilizing the pH and alkalinity, with no bleach attack AKA shock treatment. This was following pool store advice, but now I know better; whilst I don't regret working on the pH and overall chemistry, shock treatment really is the key. From the moment when I started chlorinating agressively with Liquid Bleach, it took only 5 days to really clear this thing. At its peak, my shock treatment was 4 gallons of bleach in a night; overall, I might have poured in approx. 7 gallons of bleach + a few pounds of calcium hypochlorite (in the early stages only, before I knew more about BBB methodology), along with my tablets in the floater.

Moderators, I believe we can now close this thread. I know that I will certainly need a lot more work to get this pool crystal clear, and will certainly benefit again from your experience! But at least now, the invasive green algae issue (topic of this thread) has been dealt with and I can move on to other phases.

Over the course of the summer, I intend to:
-keep chlorinating with tabs once in a while, whenever I leave for a few days and to get some stabilizer in the pool (not to often)
-otherwise, keep chlorinating with bleach for maintenance and keeping in the 5ppm range
- use algaecide very sparsely, just to help with prevention when the water gets a little blurry and that I feel unsure about algae resistance
- monitor my water chemistry and adjust accordingly (Cl, pH, Alk, CYA); I intend to to at least one trip in the USA so that might be the opportunity to invest in that Taylok K2006 testing kit!


Thanks again AnnaK and PoolDoc for the support!