Greetings from Argentina!

[ematiu]

Hello TFP Members!

I have been reading your forum for sometime, so I thought it was time to introduce myself, and thanks you for all the useful information I have read here!

I own a 70,000l ~ 20,000gal pool in Tucumán, Argentina. The pool sits near the house with is itself in a mountain lader. That means that some walls of the pool are overt the land. I decided to make 4 windows in the pool, 2 look to the garage and 2 to a living room downstairs. I am attaching some photos. It took me almost 2 years to find a good solution for sealing the windows But they are OK now.

Also, the pool has a infinity border, which I (badly) design myself. This season I added a 1000l (340gal) tank to fix the catch basing design, and it is finally working OK. I will be happy to assist any member of this.

I am working now on DIY acid feeder. I will post photos later.

Thanks a lot TFP!!
matías

 

[chem geek]

Welcome to TFP!

That's a beautiful and very interesting pool design with great views. Are those Trichlor feeders I see in the first picture? Is it difficult to get chlorinating liquid or bleach where you live?

 

[ematiu]

@chem geek, Thank a lot!!

You are right about the feeders. The most common way to maintain a pool here is using chlorine pellets + algaecide + chlorine in powder. Chlorine Liquid is also common, but i find that pellets + powder are easier to handle. Also, my PH tends to be always high, so I think that pellets, is better, right?


One problem I faced is that I used to use a lot of acid to decrease PH, but my pool's finishing is "Aquavations" (http://www.aquavations.com/, does anyone know it?) and is does not handle the acid very well. I had to polish the whole pool last month, it took me for ever :-/

That is why I am thinking now of doing a acid feeder, using drip irrigation components, in order to feed the acid very slowly...hope it helps!

 

[jblizzle]

Welcome to TFP!!!

I agree that is a very nice pool!!!

Some of your last statements seem odd to me. Generally exclusively using chlorine tablets which are very acidic results in the pH and TA being too LOW ... and not requiring any acid as you state is required.

If you have done much reading here you will also realize that these tablets (and some of the powders) continually add stabilizer (CYA) which directly is related to the required amount of chlorine that must be maintained to prevent algae (and of course we think algaecide is hardly ever needed and a waste of money).

Can you post up a full set of test results for your pool water and the water you use to top off the pool? What do you use to test?

Something just does not add up with a need for acid and heavy use of tablets/pellets/pucks.

 

[chem geek]

I suspect that the tablet feeders are set to a low output and the chlorine is supplemented by Cal-Hypo granular and that the TA is too high so that the pH still tends to rise. The vanishing edge spillover leads to a lot of aeration so will tend to make the pH rise. As Jason said, if you give us your water chemistry parameters, then we can help you dial them in so as to not require as much chemical usage. We'll need FC, CC, pH, TA, CYA and CH, if you have all of them (I suspect you don't have access to a Taylor K-2006 or TFTestkits TF-100 or equivalent test kit).

 

[jblizzle]

Ah, good point about the aeration raising the pH ... of course the answers lie in the test results

 

[ematiu]

@jason, thanks a lot!! Sorry for not posting the test results before.

I only have available PH/FC:
PH: 8.2
FC: 3ppm

My tablets wont decrease the PH. I am using 3' 3-in-1 tablets, 2 per week. My complete
maintenance schedule is:
- 2x 3' 3-in-1 tables per week. Any previous tablets left overs I throw to the catch basin's feeder.
- 1kg (2pounds) of shock chlorine powder every week (feed after usage or rain).
- 0.7L (23oz) of algaecide every 15 days.
- vacuum every week (I have a very near avocado tree...)
- 8hrs sand filtration a day (~ 130% of pool volume)

I know I am overusing the filter and some chemicals, but I am a little paranoid since
last summer I had a lot of algae problems.

Three more things:
1) It is very hot and humid here: 30C to 40C (including nights!) (80F to 100F), during summer.
2) The water of the pool is from a drilled well. I know that TA is high, but I dont know the number.
3) The pool finishing is "aquavations' hydrazzo" (http://www.aquavations.com/). Last year I used
a lot of acid, and the pool become very rough, I had to polish the hole pool this year (took me for ever!!)
so I am trying not to use it now... Would it be possible to keep a good pool condition with a PH of 8 or so? Or
I should build a very slow acid feeder?

Any tip or comment on the schedule is more that welcomed. Thanks a lot!

 

[jblizzle]

Are you sure the roughness was from acid? Our could it have been calcium scaling from your pH being too high?

There is no way to know the condition of your water without a full set of test results. Without, we are just guessing.

 

[ematiu]

Are you sure the roughness was from acid? Our could it have been calcium scaling from your pH being too high?

mmm... I never thought about that. I did the polish myself: I can tell you it was a very strong, whitish layer of rough, in the bottom and walls.... maybe it was calcium, it does make sense. There were also some parts of the finishing that were burned out buy the acid clearly, but that was in the shallow area (1ft deep).

Do you need all: FC / CC /pH / TA / CH / CYA data for a diagnosis? I think I can take a water sample to a lab to have it tested.

 

[Patrick_B]

Welcome, and that is one nice and very interesting pool design. I really love it. All those numbers will be very helpful indeed, but the FC and CC numbers won't be any good and hour after taking the sample, so you'd have to get it to the lab soon. Preferably in under 30 minutes really. I can't now, but will look at the website on the finish and weigh in on that If I can add something later. Glad you joined us...Welcome again, this one from Texas!

 

[BoDarville]

ematiu:
Welcome to the forum Very nice pool!

I support what the others have said about the importance of test results to adequately assess your pool's water chemistry.

The following things caught my eye...

My tablets wont decrease the PH. I am using 3' 3-in-1 tablets, 2 per week. My complete
maintenance schedule is:
- 2x 3' 3-in-1 tables per week. Any previous tablets left overs I throw to the catch basin's feeder.
- 1kg (2pounds) of shock chlorine powder every week (feed after usage or rain).
- 0.7L (23oz) of algaecide every 15 days.

1. What are the active ingredients in the 3-in-1 tablets? Suspect that an algaecide is one of them.[/*:m:310svngj]
2. What kind of shock chlorine powder are you using (dichlor, cal-hypo, other?)[/*:m:310svngj]
3. What is the active ingredient of the algaecide you are using? Algaecide is not needed in a properly chlorinated pool and you may be double-dipping on this depending on your answer to my question 1 above. [/*:m:310svngj]

 

[ematiu]

@Patrick, thanks for the welcome

Good to know about the 30minutes time. I wont be able to use a lab then, since my house is far from the city :-/

I will try to get one of the Taylor tests next time me or a friend visit the states, but until that I need to keep the pool running

Thanks!

 

[ematiu]

@BoDarville thanks for the welcome and for your comments!

ematiu:
The following things caught my eye...

My tablets wont decrease the PH. I am using 3' 3-in-1 tablets, 2 per week. My complete
maintenance schedule is:
- 2x 3' 3-in-1 tables per week. Any previous tablets left overs I throw to the catch basin's feeder.
- 1kg (2pounds) of shock chlorine powder every week (feed after usage or rain).
- 0.7L (23oz) of algaecide every 15 days.

1. What are the active ingredients in the 3-in-1 tablets? Suspect that an algaecide is one of them.[/*:m:5r4re0s1]
2. What kind of shock chlorine powder are you using (dichlor, cal-hypo, other?)[/*:m:5r4re0s1]
3. What is the active ingredient of the algaecide you are using? Algaecide is not needed in a properly chlorinated pool and you may be double-dipping on this depending on your answer to my question 1 above. [/*:m:5r4re0s1]

1) 3-in-1 tables data sheet:
Trichloroisocyanuric acid tablets
- Triclorine -S-triacionotriona
- Algaecide
- "Clarifier"
2) Dichlor (Dicloro-S-triacionotriona, 60%)
3) Benzalkonium chloride

thanks a lot!

 

[chem geek]

So 2 3" Trichlor tabs, if they were pure (yours are not) and were 8 ounces weight, in 20,000 gallons would increase Free Chlorine (FC) by 5.5 ppm and the Cyanuric Acid (CYA) by 3.3 ppm and lowers Total Alkalinity (TA) by 3.9 ppm (after chlorine usage/consumption). The 2.2 pounds of Dichlor (assuming the 60% meant to be 56% available chlorine and not 60% concentration of Dichlor) would be 7.3 ppm FC and 6.6 ppm CYA and lowers TA by 2.6 ppm -- if the 60% meant Dichlor concentration with the rest some sort of filler, then this would be 4.4 ppm FC with 4.0 ppm CYA and lowers TA by 1.5 ppm.

So your daily FC is to 1.4 to 1.8 ppm depending on the interpretation of the 60% Dichlor. That sounds about right given the likely high CYA level and low FC/CYA ratio so the chlorine loss rate would be lower than the 2 ppm FC per day average (also your pool may have some shade).

The CYA level would climb by 31 to 42 ppm per month. This is why you need the algaecide to prevent algae growth because you are not proportionately raising the FC level as the CYA level climbs. On the other hand, it sounds like you may get some dilution from rain overflow.

The TA would drop by 23 to 28 ppm per month so would require periodic additions of baking soda ("alkalinity up").

The algaecide you are using is the type that would normally foam. Do you find that there is foam in your spillover catch basin?

In your situation, if you do not have access to unstablized chlorine (especially chlorinating liquid or bleach), you would be better off using more Trichlor tabs and less Dichlor. This is because the Trichlor will increase the CYA more slowly and also because it will be more acidic so should help control your pH better. Over time, you will need to restore the Total Alkalinity (TA) by adding baking soda, but I suspect your TA may still be on the high side if you have been trying to maintain it. If you are not adding anything to maintain TA, then eventually your TA should get low enough for you to see the pH not rise and eventually it will start dropping and then crash (which is bad).

 

[ematiu]

I just bought some HTH (http://www.hthpools.com/) strips that measure TA, pH and FC. I also measured the water sample with my HTH liquid pH and FC to double check, and finally I tested the water from the network (which in my house also come from a close drilled well).

Here are the results:


Pool water
> HTH Strips: FC: 0.5; pH: ~8.2; TA: ~240 (not exactly the same color, I am getting a blue that does not fit the scale well)
> HTH Liquid: FC: 2-3; pH: 8.2.

Tap Water:
> HTH Strips: FC:0; pH: 7.6; TA:240
> HTH Liquid: FC:0; pH: 7.6

Reading: pool-school/lowering%20total%20alkalinity It seems that because my high TA, the roughness theory of Jason (due to calcium accumulation) makes sense!

So, I will try to follow that procedure to lower my TA and pH, using muriatic acid. Does it make sense for you?

BTW, the water looks very good now, maybe a little milky.

 

[duraleigh]

I only read your last post but you seem to have overlooked that there is little to no chlorine in your pool. If you want your pool to stay clear, you must constantly replenish chlorine. It's the single most important parameter you test. Yours is too low.

 

[ematiu]

I only read your last post but you seem to have overlooked that there is little to no chlorine in your pool. If you want your pool to stay clear, you must constantly replenish chlorine. It's the single most important parameter you test. Yours is too low.

Thanks Dave. Yesterday my FC is 3 according to the liquid HTH test! I think that the strips are giving me bad readings. They are old, I will take them back to the store.

BTW, I used to live in Raleigh! Working for Progress Energy

 

[Patrick_B]

Yea, you can't depend on those strips, even when they are fresh, especially multi-analyte types. Also, make sure you understand that FC has to be in proportion to what the Cya level in your is at. I can't say enough how much I like the pool, the addition of windows is so cool, but I love the overall design with so much negative edge. What prompted you to design and build it in such a way?

 

[gillsgonewild]

ematiu , you said you use to work in Raleigh,nc for Progress Energy? I work near and around Charlotte, nc for Duke Energy who merged with Progress. do you no longer work for progress, I know we have some teams in Argentina

 

[ematiu]

ematiu , you said you use to work in Raleigh,nc for Progress Energy? I work near and around Charlotte, nc for Duke Energy who merged with Progress. do you no longer work for progress, I know we have some teams in Argentina

Right! I didnt know about the merge with Duke. I was actually a consultant for Progress. I worked for 6 month at their building in Raleigh downtown, working on Fortran programs for their Brunswick power facilities at (I'm a nuclear engineer).

thanks for the info, nice to meet you!