Chem. Advice please

[Im-A-Duck]

After each use of my tub of course I have to add dichlor, but also my pH reads 8 or above before adding dichlor, so I have to add pH down and in turn I have to add TA up because of the chemical I am adding to lower my pH. I run my CH around 180-200. Is there anything I can do to lower the chemical usage? Is this normal for the pH to shoot up after each use? After I do threatment my water stays pretty much dead on until the next time I use it, then my pH is sky high again, is this normal?

I am wondering about a pH lock but you cannot use it if CH is 150 ot above. If you drop your CH to use this doesn't it increase your chances of scale or deposits on the heating element?

[jfish63]

Are you using test strips to measure the PH?

[Im-A-Duck]

I use a Taylor test kit for all testing. My dealer said that the pH will increase higher for some people... chemicals in the body maybe?

Is it safe on the heater componants to lower the CH below 150 in order to use the pH stabalizer?

[tileman]

I use a Taylor test kit for all testing. My dealer said that the pH will increase higher for some people... chemicals in the body maybe?

Is it safe on the heater componants to lower the CH below 150 in order to use the pH stabalizer?

I am a dichlor, taylor user myself.
Try bringing them both down to about 7.2 ppm and 80 ppm together with sodium bisulfate, then bring them back up individually with baking soda for the alk and soda ash for the ph. Both of those chemicals have little or no effect on the other.

[anne]

I have learned here not to rely on pH readings immediately after using the tub, as the aeration of the jets, etc, affects pH. If I do nothing and wait a few hours, it comes down.

Contrary to Tileman's statement, I find that baking soda increases my pH as much as it does my TA, assuming that my pH is not already above about 7.8. It is frustrating.

With *high CH you'll get scaling/deposits; with low CH you can have erosion/etching. I think recommended CH levels are 150-400. With harder water, you can have scale formation.

I have not seen too many fans of pH lock here. I'd try to first measure your pH before using the tub, and perhaps it is not as all over the place as you think.

[tileman]

I have learned here not to rely on pH readings immediately after using the tub, as the aeration of the jets, etc, affects pH. If I do nothing and wait a few hours, it comes down.

Contrary to Tileman's statement, I find that baking soda increases my pH as much as it does my TA, assuming that my pH is not already above about 7.8. It is frustrating.

With *high CH you'll get scaling/deposits; with low CH you can have erosion/etching. I think recommended CH levels are 150-400. With harder water, you can have scale formation.

I have not seen too many fans of pH lock here. I'd try to first measure your pH before using the tub, and perhaps it is not as all over the place as you think.

Unless your ph is really low(like under 7.2) baking soda will have little effect on raising your ph. This is because baking soda has a ph of 8.0 naturally. It would take alot to move it up once it's in the 7.4 to 7.6 range. This is why it's reccommended to raise alk with it when ph is already in range. That's why I said to lower them together then raise ph w/ soda ash(no affect on alk) and raise alk with baking soda(little affect on ph when properly balanced).  

[Tman122]

I have learned here not to rely on pH readings immediately after using the tub, as the aeration of the jets, etc, affects pH. If I do nothing and wait a few hours, it comes down.

Contrary to Tileman's statement, I find that baking soda increases my pH as much as it does my TA, assuming that my pH is not already above about 7.8. It is frustrating.

With *high CH you'll get scaling/deposits; with low CH you can have erosion/etching. I think recommended CH levels are 150-400. With harder water, you can have scale formation.

I have not seen too many fans of pH lock here. I'd try to first measure your pH before using the tub, and perhaps it is not as all over the place as you think.

I agree with Anne. I find my PH and TA go up together with the use of sodium bicarbonate (baking soda)

However the erosion /etching thing I'm not to sure about, I'm kinda in the school that it happens to concrete/grout/masonary tubs and pools but PVC/Acylic/SS heater, I dout it. Some still say it's important on modern hot tub/spas but I have never worried about it. Scale formation yes but etching? So I ould think to low would not matter but to high may?

[windsurfdog]

However the erosion /etching thing I'm not to sure about, I'm kinda in the school that it happens to concrete/grout/masonary tubs and pools but PVC/Acylic/SS heater, I dout it. Some still say it's important on modern hot tub/spas but I have never worried about it. Scale formation yes but etching? So I ould think to low would not matter but to high may?

Water with low pH (elevated acidity) would be more than happy to attack the metal in your pumps and heater...possibly seals as well.  This is why the recommended RANGE for pH is 7.4-7.6.  If there were no problems with pH being too low, there would not be a range consisting of upper and lower limits.  Ignore low pH and pay....

[tileman]

I have learned here not to rely on pH readings immediately after using the tub, as the aeration of the jets, etc, affects pH. If I do nothing and wait a few hours, it comes down.

Contrary to Tileman's statement, I find that baking soda increases my pH as much as it does my TA, assuming that my pH is not already above about 7.8. It is frustrating.

With *high CH you'll get scaling/deposits; with low CH you can have erosion/etching. I think recommended CH levels are 150-400. With harder water, you can have scale formation.

I have not seen too many fans of pH lock here. I'd try to first measure your pH before using the tub, and perhaps it is not as all over the place as you think.

I agree with Anne. I find my PH and TA go up together with the use of sodium bicarbonate (baking soda)

However the erosion /etching thing I'm not to sure about, I'm kinda in the school that it happens to concrete/grout/masonary tubs and pools but PVC/Acylic/SS heater, I dout it. Some still say it's important on modern hot tub/spas but I have never worried about it. Scale formation yes but etching? So I ould think to low would not matter but to high may?

I must have some pretty strange water than I guess.
My ph was 7.5ppm and my alk was 80ppm the other day, so I added just over 1 oz of baking soda. Today I tested my water again and ph was still 7.5 while my alk was now 100ppm. Taylor doesn't lie and neither do I. Hey that rymed. It's weird how chemicals reaact differently to eachothers water. :-?

[anne]

As far as the etching goes, I believe that you guys are right: it is supposed to be a plaster/concrete/etc issue, but since my manual warns against too low a CH level, and soft water is not recommended, I figured that there were still ceramic parts in the heater or something that could get etched. No personal knowledge, though.

As for baking soda's effect on pH, I understand that it is *supposed to affect TA a lot more than pH but here's my experience: I looked over my log book (yep, recorded for learning purposes!) and on average I'd see my TA increase about 10 for every TBSP baking soda added. This is a rough estimate, but now if I want my TA to go from 70 to 100, for example, I add 3 TBSP. The increase in pH is not so predictable, but it is almost always at least 0.2 units to 0.4 units up adding 2-6 TBSP. Now, that is not a huge change, but it is still significant. In hind site, I think there must have been other factors, too, since there were a few times that I added 4-6 TBSP and the pH went for 7.0 to 8.0. This is all with a Taylor kit, BTW.

[tileman]

As far as the etching goes, I believe that you guys are right: it is supposed to be a plaster/concrete/etc issue, but since my manual warns against too low a CH level, and soft water is not recommended, I figured that there were still ceramic parts in the heater or something that could get etched. No personal knowledge, though.

As for baking soda's effect on pH, I understand that it is *supposed to affect TA a lot more than pH but here's my experience: I looked over my log book (yep, recorded for learning purposes!) and on average I'd see my TA increase about 10 for every TBSP baking soda added. This is a rough estimate, but now if I want my TA to go from 70 to 100, for example, I add 3 TBSP. The increase in pH is not so predictable, but it is almost always at least 0.2 units to 0.4 units up adding 2-6 TBSP. Now, that is not a huge change, but it is still significant. In hind site, I think there must have been other factors, too, since there were a few times that I added 4-6 TBSP and the pH went for 7.0 to 8.0. This is all with a Taylor kit, BTW.

Hopefully I will not let my alk go that low so I won't have to worry about adding that much baking soda. I'm still a newbie at heart to all this chemistry but I'm very particular about the things I do. I'm testing my water every other day so there has been no surprises for me yet.
In my short time as a spa owner I found that it's much easier to maintain the water with this kind of regimen. It only takes a couple of minutes for me to test all levels so I don't think my regimen will change over time.
I tend to favor adding small amounts more often opposed to large amounts less often. Don't get me wrong I'm not adding chems at ever + or - but I do however keep a close eye on how things are doing so when I do drop/gain 20 ppm or .2ppm, I'm ready for action.
Btw, my tub is only 336 gallons and 1TBSP OF BAKING SODA adds 10-15 ppm.

[CapMorgan]

I use Pro Team chemical’s and when I use the PH down if I want to lower both PH and TA I just add it straight to the water, but if I just want to lower the PH and not the TA I mix 1 ounce of PH down to 10 ounces of the spa water in a container and then I pour it evenly around the edge of the tub and then just my Ph gets lowered.

CapMorgan

[Tman122]

However the erosion /etching thing I'm not to sure about, I'm kinda in the school that it happens to concrete/grout/masonary tubs and pools but PVC/Acylic/SS heater, I dout it. Some still say it's important on modern hot tub/spas but I have never worried about it. Scale formation yes but etching? So I ould think to low would not matter but to high may?

Water with low pH (elevated acidity) would be more than happy to attack the metal in your pumps and heater...possibly seals as well.  This is why the recommended RANGE for pH is 7.4-7.6.  If there were no problems with pH being too low, there would not be a range consisting of upper and lower limits.  Ignore low pH and pay....

Tileman, sorry I didn't make myself clear I was talking about Calcium hardness and it's importance. I would never allow my PH to go out of range, as the importance of the acidity of the water is genuine. Calcium and it's ability to precipitate itself from concrete like surfaces is what I was talking about.

[tony]

I use a Taylor test kit for all testing. My dealer said that the pH will increase higher for some people... chemicals in the body maybe?

Is it safe on the heater componants to lower the CH below 150 in order to use the pH stabalizer?

I have never seen anyone recommend pH stabilizers.  It can cause more problems than it fixes.  Keep working to get your pH and TA in line.  You didn't mention your TA level.  Too high may draw your pH up.

I keep my calcium levels just over 100.  I don't believe in the need to raise it higher than that.  Out of the tap it is 50.  I raise it just for the extra clarity in harder water.

[Im-A-Duck]

Thanks Tony, finally someone with advice on my question about the stabalizer.

I keep my water as follows: Cl- 2-5; pH 7.5; TA 90-100; CH 200.

I have a 320 gal Caldera Martinique.  

Once my wife and use the tub for 30-45 minutes it looks like this:
CL-0, pH>8; TA 90-100; CH i don't check.

I add 2 tsp dichlor, 2.5 tbs pH down, 2 tsp TA up. and by doing this my water is perfect the next morning.

Does this seem normal as for as chemical usage? and what is going on with the water?