Help for a pool owner in Brazil

[frankinbahia]

Hope I'm the right/best forum!

I’m unable to get my pool back to blue. It’s currently very green but not turbid (you can see the bottom at 6’). Here’s the situation and history:

1. The pool is ceramic tile, 17k gal fresh water, in-ground.
2. I live in Brazil, and the pool is about 100yds from the ocean. There are no trees or other vegetation nearby.
3. Until a week or so ago, it was always deep blue and crystal clear (just like the ad photos!), and very easy to maintain.
4. The only different event which immediately preceded the pool going green was the installation of a solar heating system (pvc pipes). To do the installation, I had to lower the pool below the returns (about 2’), then refill.
5. Here are the numbers:
- Cl (dichlor granules) = 3.0+ (I shocked it)
- pH = 7.4 (I had to add a lot of soda – it was very low)
- Tot.alk = 100
6. There was a considerable accumulation of algae on the bottom, which I vacuumed out. But the water remains green. (When I take a sample in a water glass, however, it appears perfectly clear.)

Thanks for your help!
Frank

 

[Stuamurr]

Welcome to the forum!

We will be happy to help out!

Because you are using Di-Chlor I would hazard a guess your Cyanuric Acid level is very high, therefore slowing down the efficiency of your Free Chlorine residual. Do you have the ability to test for everything else? In order to help out we really need some more in depth figures:
FC (Free Chlorine), CC (Combined Chlorine), pH, TA (Total Alkalinity), CH (Calcium Hardness), CYA (Cyanuric Acid)
Once we have all these parameters we will be able to help out, what test kit are you using for your pool?

Meantime however, I would be adding more chlorine in the form of Plain, Unscented Bleach from your supermarket or Sodium Hypochlorite to boost up your chlorine level (I suspect your shock level is going to be higher than 16ppm FC) If you are using Di-Chlor exclusively you should cease immediately, the same applies to pucks, I don't know if you can use Calcium Hypochlorite as I don't know your CH level.

 

[frankinbahia]

First - thanks for your quick and helpful reply. I can see why you pop up on the first page of a Google search!

Unfortunately, the tests I reported are the only ones available in rural Brazil. (They don't call this Third World for nothing!) When I go to the big city next month, I'll get a full test kit. The one I'm using is a Rainbow Lifeguard HR78. I will also try the bleach and will let you know the results.

Thanks again!

 

[frankinbahia]

Another quick question: The sodium hypoclorite sold here is 2 to 2.5%. Does that sound good?

 

[msgtdan]

Very weak, here in the U.S. it's usually 6% to 12.5%. Most Clorox is now at 8.25%. Usehttp://www.poolcalculator.com/ to figure your amounts needed. You have to set it up for your pool first.

 

[Stuamurr]

We will certainly do our best to help out. I ran a search and cannot find the testing product you mentioned. Are they test strips? I would be wary of being able to pick up a test kit that will do what you want, without purchasing online, I know you would be unable to get the tf100 kit but may be able to get the Taylor K2006 shipped to you from this link: http://tftestkits.net/Taylor-K-2006-p27.html

You may well find you get sold a kit that does not do the job for you, is too expensive and does not test chlorine above 4-10ppm which is going to be essential for you.

Try and find a better source of bleach as 2% is ridiculously low and you will need so many jugs manual handling will be a nightmare! Also investigate the supply of Sodium Hypochlorite which comes in far higher strength.

Do you have soft water or hard water if you are aware of the term? If you have soft water Calcium Hypochlorite may be a suitable, but you would need to know your Calcium Hardness levels at present and that of your source water.

With green water now, I think you have a very high CYA level, algae has gotten a hold, so you need to shock, see pool school at the top for more info on the process, it may take a while and a lot of your work meantime will be guesswork until you get a decent way to test your water.

And finally is water expensive where you live? you may need to partially drain & refill of your pool to get to manageable levels

 

[frankinbahia]

Stuart - the kit (not strips) is one I bought in a pool supply store in the States. But I gather that the TF100 is the gold standard. I'll be in the US next month and will get one. Re the water, I'm pretty sure it's hard -- it's well water and has a high iron content which I treat with a bit of aluminum sulfate.
Dan - thanks for the calculator link.

Thanks to ALL for your suggestions. I'll do an update when I've made some progress and have the kit.

 

[jblizzle]

Be aware that the TF-100 is only available from tftestkits.net. So if you want one, you may have to order to have it delivered to wherever you are staying.

Which kit did you buy already? You may just be missing the FAS-DPD chlorine test depending on what you already bought.

 

[Durk]

I have some experience in helping to manage pools in Brazil (one in Itú and one in São Paulo). The availability of good LC in appropriate quantities and test equipment/reagents in the sticks is basically zero. The one redeeming factor is a lot of free water from rainfall just about anywhere (Rio has annual rainfall exceeding 1.1 meters to give you an idea.) I tried to use a mix of Cal-hypo and pucks and a little drain and fill along with the rain to manage CH and CYA.

Bleach is typically sold in these ridiculous little 1 liter plastic squeeze packs that would drive you nuts for pool use.