Nitro
-
Posts
779 -
Joined
-
Last visited
Posts posted by Nitro
-
-
Two things. First, your CD is actually higher than 70%, because you didn't wait ~24 hours to test the second time. Second, just because your CD is normal doesn't mean your tub is free of biofilm, which can cause problems. I recommend doing a Decon (bringing FC up to 100 ppm) regardess.
-
Nitro, I am definately going to take your advice. Who am I to swim upstream against the experts. One question however - in step 11 of your Decon instructions you state to shock with Dichlor to 10ppm. How do I calculate 10ppm? Use the pool calculator? Of course this comes after balancing right? I have hear/been told that the correct way to balance is in this order 1) CH ~150ppm, TA ~80ppm and finally PH ~7.2?
The Pool Calc will do it for you. It takes approx 1 oz Dichlor to raise FC 10 ppm in a 400 gal tub.
A CH over 100 is ok, just make note of it. Bring your TA down to 80 ppm for the first week while using Dichlor. After you build up 30 ppm CYA, switch to using bleach as your sanitizer, and lower TA to ~60 ppm. Read my top link below for full details.
-
I think you mean NewB@spa, and not myself?
Yes I did. Thanks for the correction.
-
NewB, IMHO your tub is not safe, because you've let FC drop to zero for too long. You have a VERY high Cholrine Demand, so that makes it even harder to keep FC up. I seriously recommend doing a Decon, preferably with Spa flush. However if you don't want to (can't) change your water twice you can just do this.
Add 1-2 Cups MPS, then 1 Gallon of bleach.
Let jets/air run for an hour, and let sit for a few more.
Wipe down spa (and cover) with super chlorinated water.
Check FC.
At this point I recommend refilling. However, if you don't want to refill yet, you can add Hydrogen Peroxide to lower your FC. It will take approx 1 cup to lower your FC by 10 ppm. I would lower FC to around 50 ppm if not already there, then let sit overnight. Check FC again to see what your CD is. If CD is 50% or below, you're good to go. Then do a refill ASAP.
-
Nitro - I am leaning towards your method of maintenance when I refill (not certain when I will do that). I have had my new tub approx 2 months and I am now having issues with getting FC up. Water tested yesterday @ dealer was FC 0, TC 17, TA 90, CH 300, CYA 60 (although they said my MPS - EZ Spa could be making that inaccurate). So to get back on point here - if/when I do decontaminate/refill in your explanation of calculating CD you state to get FC to 10ppm - how do you do that? How much dichlor in a ~400 gal tub will that take? Of course that comes after balancing (PH, TA, CH) right? Also what type of tester do you recommend? I am leaning towards a ColorQ 7 (electronic), but everyone seems to use Taylor...
Keep in mind if this is a new tub, you will want to change the water after a month or two anyway. After this first refill, the water should last ~6 months.
You can use the Pool Calculator to calculate how much chems you need based on tub size. It your case (400 gal), you should add an ounce of Dichlor. It doesn't have to be exact for calculating CD. Just measure it and make note.
I use, and recommend the Taylor K-2006 drop test kit. I don't have experience with electronic testers.
-
TA won't rise unless you add something to make it rise (i.e. Baking soda). Bleach alone should not have effected your TA. I believe there must have been an error in testing. I suggest you measure TA/pH again, and make sure you get an accurate reading. I assume you're using a drop test kit, and not test strips. Then proceed from there. i.e. Lower TA as needed.
-
I agree that if the alkalinity is definitely high then the "Lowering Alkalinity" method is the best way to go.
However, once the alkalinity is close, then adjusting the pH only will slowly tune in the proper alkalinity without overshooting the balance point.
The carbonate alkalinity is what is going to determine the rate of pH rise due to the loss of carbon dioxide.
The poster's carbonate alkalinity is already less than 50 ppm. I think that that's low enough to start fine tuning the alkalinity by only lowering the pH.
I think we are pretty much saying the same thing. I just like to track it so I get a handle on where it needs to be. BTW, carbonate alkalinity may need to go as low as 40 to gain pH stability.
-
You don't.
Allow the alkalinity to stay where it keeps the pH stable at the desired level. If your pH is constantly rising, then your Alkalinity is too high. If your pH is constantly dropping, then your alkalinity is too low. If your pH is staying within a good range, then your alkalinity is just right.
Adding 50 ppm of boric acid/borates will also help reduce unwanted pH rise.
So if the ph is 8.3 and I add acid and the ph goes up again I add more acid. I keep doing this until I the ph stays in the midrange, ignoring how low the alk becomes? I'm thinking it will be very low if I do this?
Yeah, but it should happen with TA around 50 ppm. As Quant said, add Borates to slow pH from rising.
-
Hey Nitro,
Great quick ref. guide. Thanks. BTW, I adjust the calcium hardness first then pH & TA. Is that not the correct procedure? The CH will dictate the needed pH & TA.
Also, I add BORAX (as borates). I use it to raise pH when/if it drops but don't go out of my way to use it as a buffer. Do you think it warrants a step in the process?
Greg
BTW, just over one month and a half now using this exact formula and things are looking great. I barely need to adjust anything...(using allot of bleach though ;-)
You can adjust CH before or after. Unless it's much lower than 100ppm, I wouldn't touch it. Just make note.
Using the tub's jets/air should raise pH if TA is too high, so I'm not sure the need to use BORAX, other than to add Borates during startup.
-
Guess I'm the slow one here. LOL
-
I've had trouble with my ph rising to 8.3 over time (starts around 7.5 upon refililng). My alk is usually around 60-80 when I refill. When I add muriatic acid (dosage according to pool calc.) to bring the ph down of course the alk drops even more. How do I bring it up without bring up the ph?
You don't!
Instead, adjust TA until pH is stable, below ~7.8. That means you need to lower your TA to ~50 ppm if needed.
-
I wouldn't worry about lowering your alkalinity. Just add the acid to lower the pH, and the alkalinity will take care of itself.
If your pH goes back up, just lower it back down. After a few times, the pH will stop rising and it will stay where you put it.
This is where we disagree. I prefer to speed up the process by lowering TA until pH stops rising. This can be done in a few hours.
The reason is, some people have very high TA levels (300-400). In which case it will take them a long time (if ever) to get their pH stable, without paying attention to TA. Therefore, I find it's better (easier, less trouble) to adjust TA (to 60-80) from the get go, and fine tune over the course of the next few days, weeks.
-
Don't mess around with a used hot tub, decontaminate!
I totally agree! You have nothing to lose, and I nice clean, safe tub to gain.
-
I recommend you Decontaminate first (see below).
Then follow the Dichlor/Bleach method. Use Dichlor of a week or two to build CYA to 20-30 ppm, then switch to bleach. (see bolw)
I'm not familar with electronic testers. I would consider getting a good drop test kit. Taylor K-2006
-
My pH rises to ~7.8 after I use the tub, and drops to ~7.6 before the next soak.
To answer the question. Lower TA until pH stays at or below 8.0 when the jets are on.
-
Here is a quick reference to using the Dichlor/Bleach method. (i.e. Chlorine)
Please see the full guide for a detailed explanation. Top link below.
Initial Startup Procedure
1. Balance water by lowering TA to ~80 ppm. See link below (Lowering TA)
2. Aerate until pH is consistently 7.4-7.8. Lower TA if pH rises above 7.8. Raise TA if pH stays below 7.4.
3. Test Calcium, and make note of it. (100-150 ppm) is ok.
4. Add 50ppm Borates (highly recommended)
5. Shock tub to 10 ppm FC using Dichlor the first night after filling.
6. Wait 24 hours and test FC again in order to calculate Chlorine Demand. (See link below)
7. Start using tub.
8. Continue to use Dichlor after soaks (approx 7 ppm FC per person per hour) (or 3.5 tsp)
9. After you have added ~34 ppm FC (~30 ppm CYA) using Dichlor, switch to Clorox 6% unscented bleach. Takes about a week or so.
Ongoing Maintenance
After the initial startup procedure above, you'll basically do the following:
Check FC every day or two (and before soaks).
Check CD as needed (once a week to start).
Add plenty of Chlorine after soaks (and as needed) so FC NEVER drops to zero, and CD stays low.
Add MPS before/during high bather loads to help out the Chlorine, and keep CD low. (Optional but recommended)
Check pH once a week, and adjust TA as needed.
Rinse filter every week or two, depending on use.
Check CYA every 3 months, and raise by using Dichor if needed. CYA will drop slowly over time.
Use Sea Klear (clarifier) if you experience foam, or cloudy water.
Water Change
After 6 months, change water and start over.
If this is a new tub change water after the first month, then continue bi-yearly.
Consider using a Spa Flush to clean out pipes before draining 1-2 times a year.
Clean filter with TSP every water change.
Lastly, if you let the FC drop to zero for any length of time, the tub is prior owned or you're having serious medical issues (i.e. rashes etc.), consider doing a Decontamination. (see below)
Happy tubbing!
-
1
-
-
One thing I would suggest is that people using the dichlor then bleach method not lower their alkalinity to 60 until they switch over to bleach.
Since dichlor is acidic, it might be better to target about 80 ppm while using dichlor and then lower the alkalinity to 60 once they begin to use bleach.
80 ppm would also be helpful if the person is planning to use boric acid on a new fill because the boric acid will lower the pH some on addition.
You have a good point. Although I do find even a TA of 60 ppm tends to be a little high when using Bleach. After a week of Dichlor, it usually dials in pretty well.
Why don't we split the difference and say 70 ppm? lol
-
Don't worry about getting your Chlorine level down. It will come down naturally over time, and even faster as soon as you start soaking. The key is to keep it up (above zero) at all times.
Regarding your pH/TA. Your pH is fine, however having the TA up at 120 ppm may cause your pH to rise once you start using the tub's air/jets. (i.e. aerate) Therefore you may need to lower your TA.
I'm assuming you plan on using the Dichlor/Bleach method. If so, here it is in a nut shell:
1. Balance water by lowering TA to ~80 ppm. See link below (Lowering TA)
2. Aerate until pH is consistently 7.4-7.8. Lower TA if pH rises above 7.8. Raise TA if pH stays below 7.4.
3. Test Calcium, and make note of it. (100-150 ppm) is ok.
4. Add 50ppm Borates (highly recommended)
5. Shock tub to 10 ppm FC using Dichlor the first night after filling.
6. Wait 24 hours and test FC again in order to calculate Chlorine Demand. (See link below)
7. Start using tub.
8. Continue to use Dichlor after soaks (approx 7 ppm FC per person per hour) (or 3.5 tsp)
9. After you have added ~34 ppm FC (~30 ppm CYA) using Dichlor, switch to Clorox 6% unscented bleach. Takes about a week or so.
After the initial startup procedure above, you'll basically be doing the following:
Checking FC every day or two (and before soaks).
Checking CD as needed (once a week to start).
Adding plenty of Chlorine after soaks (and as needed) so FC never drops to zero, and CD stays low.
Adding MPS before/during high bather loads to help out the Chlorine, and keep CD low. (Optional but recommended)
Checking pH once a week, and adjusting TA as needed.
Rinsing filter every week or two, depending on use.
Checking CYA every 3 months, and raise by using Dichor if needed. CYA will drop slowly over time.
After 6 months, change water and start over.
If this is a new tub change water after the first month, then continue bi-yearly.
Consider using a Spa Flush to clean out pipes before draining 1-2 times a year.
Clean filter with TSP every water change.
Lastly, if you let the FC drop to zero for any length of time, the tub is used or you're having serious medical issues (i.e. rashes etc.), consider doing a Decontamination. (see below)
Hope that helps.
-
Cramp, you do realize without a properly sanitized tub you risk serious infection to you and your family, not just white floaters. To me you sound like you're just playing games with your hot tub water, and aren't too concerned about it. I seriously recommend you start to follow the advice from the experts on this board, before you (or someone you love) gets seriously hurt.
-
To answer you question in one word, Chlorine. However, I seriously suggest you read the top link below. Then if you have any more questions, let us know.
-
So when using the dichlor-bleacik method, it is not really necessary to shock the tub? Just keep the cd up? Is that correct?
Keep FC above zero at ALL times, and CD as low as possible. Do that (along with balancing your water) and you'll never have water issues.
I don't like to use the word shock. I shock the tub every time I use it. I'd rather just say add chlorine.
-
Basically you want to balance your water (i.e. adjust TA, pH and CH). Then give it a good shock (10 ppm FC) with Dichlor.
-
Funny thing about ozonators. They will actually lower CD when there is something in the tub to oxidize (i.e. after the tub is used). However, when there's nothing to oxidize (i.e. tub not in use) the ozonator with destroy chlorine (i.e. raising CD). So what you're experiencing is consistent.
It's up to you which you prefer. If you use the tub a lot (every day or two), an ozonator will work with you. However, if you rarely use it (1-2 per week or less), on ozonator might work against you.
-
Lastly, if someone came along and said, "I'm getting rid of my pool (or spa) unless you can show me how to operate it with far less chemicals", or "I'll install a pool (or spa) if you can show me how to operate it with far less chemicals", what could they be told?
IMHO, the Dichlor/Bleach method (see below), if done correctly, uses the least amount of chemicals, is the cheapest and safest method there is. Anyone not willing to use Chlorine (or Bromine), has a much higher chance of having problems. Especially with high bather loads.
And I Thought I Had It Down!
in Hot Tub Water Chemistry
Posted
Merry Christmas and welcome to the forum.
First you shouldn't be using a floater with tabs (Trichlor) in a hot tub. The hot water will make them dissolve too quickly raising the FC. And they are too acidic which will drop TA/pH. Both of which you are seeing.
I'd recommend reading the top link below for the correct way to use Chlorine.