Low Ta And Leaking Pump Seals? Help And Advice Please...

[Venams]

I've been using this site for the valuable information and the Dichlor then Bleach method for about 2 years with success.

I recently bought a new Hot Springs hot tub (replaced my old trusted and tried Sundance Optima) a little over a year ago. I noticed 2 wets spots by the front of the cabinet just past the 1st year. I thought it was because of the recent rain but when I saw the telltale white residue I knew that my tub was leaking.

Pulled the front panel off and sure enough, 2 of the main pumps (equipped with 3 pumps and 1 circ pump) were leaking at the bushings.

I cannot believe that not only 1 but 2 pumps would be leaking this early into the tub ownership.

Placed call into Spa Repair. They came out and asked about my water chemistry. I told them look at the water, it's crystal clear and my TA is always balanced to about 50PPM while my PH remains fairly constant at around 7.5. He tells me that the TA is low and water was acidic and probably lead to the pumps premature failure?

I've been given advice to keep my TA around 50ppm so the PH won't stray and rise too much over time. Was that bad info???

Anyway, drained tub and refilled. My TA is at 70ppm and PH at 7.1. If the previous advice I was given is OK I'm assuming I should aerate tub to bring PH up and then use Muriatic to bring TA back down to 50ppm area right?

[decksandspas]

You could stand to increase your Total Alkalinity a little bit, generally I recommend around the 80ppm range. Your pH is just fine at 7.5. However, having your alkalinity at the 50ppm level that you had it at should not be the cause of your pumps leaking. You stated you have had the spa for less than a year and I personally have never seen a somewhat low TA level causing any problems with the pumps even over a greater period a time. With soft water, low alkalinity and high bromine/chlorine levels I have seen damage done to the pumps but this is seems to be a different scenario (unless the bleach is really overdosing your fcl).

I would check the connections to your pumps and find our exactly where this leak is coming from. I would guess you're looking at a connection or gasket that is loose or kinked and not corrosion or chemical damage.

Remember if the chemical methods you were using with your old spa are the same ones you are using now there should be now difference. Essentially all the spa companies use the same pumps, packs and plumbing.

[chem geek]

I am sorry you've had pump leaks in your spa. This is the first such report of anyone having this problem using the Dichlor-then-bleach method and there are many people who have been using that method for many years.

The TA is only there to maintain the pH (because the spa is not plaster so doesn't need to be saturated with calcium carbonate) so if your pH didn't get too low it wouldn't have affected the pump seals. Were you topping up the CYA monthly? CYA gets slowly oxidized by chlorine and usually drops by 5 ppm per month in spas so one needs to use Dichlor monthly for a day to maintain the CYA level. Maybe the CYA got too low so your chlorine level got too strong. You should not let your CYA get below 30 ppm. You could consider having the CYA higher if you want, but probably not much more than 50 ppm.

The problem with raising the TA can be that your pH will tend to rise, but so long as you stay on top of that it would be OK. It would just mean that you'll be adding acid to keep the pH from rising and then adding baking soda to keep the TA up. That's why you've got the TA lower now -- to not be in that vicious cycle.

Does your Hot Springs spa have any special equipment in it different from your previous spa? For example, an ozonator?

[chem geek]

Something else I thought to ask was how are you adding chemicals to the spa, especially acid if you add that to keep the pH down? Are you adding them slowly over a return flow (where the water comes into the spa) with the pump running? You aren't adding chemicals in the skimmer or near where water goes back to the pump, are you?

Whenever you add acid to the spa, the TA will drop so if you added any to keep the pH down then the TA may have become lower than 50 ppm. This is also true for net acidic chemicals such as Dichlor since chlorine usage/consumption is acidic (which is why bleach is close to pH neutral because it raises the pH upon addition and then drops as the chlorine is consumed). Non-chlorine shock is also acidic.

Did you use 50 ppm Borates in the spa?

There are other reports of leaky pump seals, but usually not occurring so quickly and as decksandspas noted some seem to be from high disinfectant levels such as an excessively high bromine level.

Pump Leak , Hot Spring Classic

Pump Seal

Leaky Water Pump

Refilled Recently Now Trying To Balance Spa Water

Nevertheless, having two pumps leak and happening relatively soon would seem to indicate something in the water causing it unless this is a rather unusual coincidence.

[Venams]

I had been using powder to bring the borates to 50 ppm but decided not to use it and just try it without this time.

My spa has an ozonator. Now that I think of it, the ozonator did stop working which resulted in my CL levels rising over the period of a week with daily addition of the bleach. I think it was about 22ppm or so. When I tested and saw the high CL I stopped dosing bleach and checked ozonator, It was dead. They sent out another one and I had it replaced. This happened about 2 months ago. Didn't associate the high CL with the pumps leaking but that might be the culprit?

[Venams]

TA is at 80ppm and PH 7.1

I was going to aerate tub to bring PH up and then add enough acid to bring TA down to 50ppm.

Does this sound right?

Or should I add borates to 50ppm and then test and proceed? Just wondering if I really need to add the borate?

[chem geek]

With the higher chlorine level, it may also have oxidized the CYA faster so that would have had the active chlorine level get high and yes that could have degraded the pump seals faster. So maybe that is what happened. It sounds like you weren't testing before each soak and just assumed things were in a steady-state. Even so, that still seems pretty fast for just one week of high chlorine to damage seals in that way. You didn't mention if you periodically (say, once a month) used Dichor to keep up the CYA level. You should probably test CYA monthly until you get a handle for how quickly it drops in your spa and then use Dichlor to keep it up as needed.

It's up to you whether you want to go back to the 50 ppm TA. I don't want a service guy refuse to honor a warrantee because of that. You could see if your pH is still reasonably stable at a higher TA of 80 ppm that won't cause the service guy to freak out. Up to you.

As for the borates, that depends on how quickly your pH rises. If it doesn't rise too fast or too high, then you don't need them, but they are an additional pH buffer that resist the rise in pH from carbon dioxide outgassing. So whereas TA from bicarbonate is a SOURCE of rising pH, the borates are not. Again, up to you, but they should help keep the pH from rising as quickly.

[Venams]

With the higher chlorine level, it may also have oxidized the CYA faster so that would have had the active chlorine level get high and yes that could have degraded the pump seals faster. So maybe that is what happened. It sounds like you weren't testing before each soak and just assumed things were in a steady-state. Even so, that still seems pretty fast for just one week of high chlorine to damage seals in that way. You didn't mention if you periodically (say, once a month) used Dichor to keep up the CYA level. You should probably test CYA monthly until you get a handle for how quickly it drops in your spa and then use Dichlor to keep it up as needed.

It's up to you whether you want to go back to the 50 ppm TA. I don't want a service guy refuse to honor a warrantee because of that. You could see if your pH is still reasonably stable at a higher TA of 80 ppm that won't cause the service guy to freak out. Up to you.

As for the borates, that depends on how quickly your pH rises. If it doesn't rise too fast or too high, then you don't need them, but they are an additional pH buffer that resist the rise in pH from carbon dioxide outgassing. So whereas TA from bicarbonate is a SOURCE of rising pH, the borates are not. Again, up to you, but they should help keep the pH from rising as quickly.

As usual THANS so much for the advice Chem Geek. To answer your questions: I really hadn't been using the tub at all. Just adding daily bleach to keep chlorine levels up. I guess I did that for about 2 months and yes I did add some dichlor here and there but didn't test CYA since it depleats so much of my FAS-DPD test kit reagent.

I'm going to be checking ALK/PH more often so this doesn't happen and I'll look for PH rise and add Boric Acid if needed.

Thanks Again Sir!

[PreservedSwine]

What type of test kit are you using?

Both shaft seals leaking is a sure sign of poor water chemistry. Unless you get a handle on it, expect the repaired pumps to last as long as the first ones, as well as other issues. It sounds as though you're on the right track, goodluck!!

[Venams]

OK. So I've been dosing Dichlor at the rate of .5oz each day per the Pool Calculator for 550 gallons.

I just tested my chlorine levels yesterday and it's at 16ppm!!! What the heck. Chlorine is high once again!

I'm confused. Pumps were just replaced and they replaced my ozonator as well so with the ozonator my chlorine demand should be higher. I just tested chlorine levels 24 hours later and it's now at 14ppm. Using the formula from this website my chlorine demand is 13% right (14/16= .87 , 1-.87=.13 or 13%)

Isn't this extremely low chlorine demand supposedly with a brand new corona discharge (freshwater III) ozonator?

There are bubbles coming out from the circ pump so I know the line is not obstructed from the venturi and the check valve was also replaced.

I'm at a loss to figure out how the chlorine levels got that high again? Anyone have any suggestions and how can I reduce my chlorine levels at this point?

[chem geek]

Yes, that is a low chlorine demand if the ozonator is working. You can add hydrogen peroxide to easily lower chlorine levels. You would need about 11 fluid ounces of 3% hydrogen peroxide (typical concentration for it in a drug store) for 550 gallons to lower the FC by 10 ppm. Basically you can use PoolMath (that's maintained whereas The Pool Calculator no longer is maintained) and put in 6% bleach and that quantity is the same amount of 3% hydrogen peroxide needed to neutralize the FC amount you put in the calculator (i.e. pretend you are increasing FC using 6% bleach, then use that same quantity of 3% hydrogen peroxide to neutralize that amount of FC).

Could it be that you actually have bromide in your water and that the ozonator is making bromine from it? You didn't add any sodium bromide or use any bromine tabs, did you?

[PreservedSwine]

You shouldn't need to be adding more than 1/2 teaspoon Dichlor if no one is using it. Personally, I add no teaspoons if not being used. But I do shock once/week with non-Chlorine shock. Toss in 1/2 teaspoon before, and 1/2 teaspoon after each use. Your chlorine will likley go to zero shorty after adding the chlorine, but that's not necessarily an issue as there shouldn't be any pathogens to multiply, and no one will be jumping in with no chlorine. It's vital to add the dichlor AFTER each use, as that's the moment when the water is as dirty as it will ever be, and needs sanitation the most. That chlorine gets used eventually, and that's why you're adding 1/2 teaspoon before each use. Enough to sanitize the water, but not too much to smell, or even notice that it's in the water.

If you're adding a tablespoon of Dichlor per day, that's too much. Not only too much Chlorine, but too much CYA as well.

[chem geek]

As PreservedSwine noted, half ounce (one tablespoon) per day is too high in between soaks. In 550 gallons that would be 3.8 ppm FC. Is this because you are soaking every day? That would be around 30 person-minutes of soaking with no ozonator or around one person-hour with an ozonator (but these are just rough rules-of-thumb). If you aren't soaking every day, then you should not add that amount in between soaks. If your ozonator is working, then the amount of chlorine you need to add after a soak is significantly less than the basic rule-of-thumb, usually around half the amount compared to no ozonator. Perhaps that is why you are getting too high. You should not be only going by a rule-of-thumb but should actually be measuring the FC level and adding whatever it takes to maintain a low FC residual, usually around 2 ppm in between soaks (not more than 4 ppm) and usually target around 1-2 ppm FC for the start of your next soak. Obviously right after a soak when you add chlorine the FC will spike, but if you are dosing the correct amount the FC should drop fairly quickly so that 24 hours later you are at your background level (2-4 if not soaking right away; 1-2 if you plan to soak the next day)

1/2 teaspoon of Dichlor in 550 gallons is 0.6 ppm FC and the daily loss if it were 25% of 2 ppm would be only 0.5 ppm FC so if your loss is even lower you'd need even less chlorine in between soaks to maintain the FC level. You need to figure this out by testing your FC in between soaks as you have done to figure out your chlorine demand and then just add the amount of chlorine needed to maintain an FC in between soaks -- the FC need not be high and 2 ppm is enough if you maintain it but I wouldn't have it be any higher than 4 ppm. Most people like to start their next soak with 1-2 ppm FC so that they don't notice the chlorine.

So you add a larger amount of chlorine proportional to your bather load right after your soak and then you add rather small amounts of chlorine in between soaks to maintain the FC level. What is confusing is that you measured a rather low 24-hour chlorine demand since with an ozonator that would usually be higher, typically 50% or higher.

Also, if you were going to use the Dichlor-then-bleach method, then you need to keep track of how much Dichlor you are adding. When you've added cumulatively around 33-44 ppm FC, then that's 30-40 ppm CYA and you should switch to using bleach. You then use Dichlor about once a month to keep the CYA up. Note that PreservedSwine mentions another way you can keep the CYA in check which is to use some non-chlorine shock instead of only Dichlor. That too will lower the rate of CYA buildup and let you go longer between water changes. Just note that both Dichlor and non-chlorine shock are net acidic so you'll have to bump up your TA as it drops over time. If you instead used bleach, then that won't happen, but you'll need to manage the pH from rising.

[Venams]

Could it be that you actually have bromide in your water and that the ozonator is making bromine from it? You didn't add any sodium bromide or use any bromine tabs, did you?

Nope. Didn't add any type of bromine.

I think I will add the 50ppm of Borate now that you explained how it keeps the PH in check. I still don't understand why my chlorine demand is so low with a brand new Freshwater III ozonator installed?