Start up on new pool with a propane heater

[moore887]

I don't do start ups. I probably never will. There's a couple of guys that follow builders around a 50 mile radius doing start ups hoping to get a pool service contract out of it. That's not for me. However, I got an interesting call today from one such guy today to caution me against taking on any new pool that has a gas heater. He said with the amount of acid required to keep the pH down, he is finding copper stains in the pool and he is personally on the hook to use whatever (jacks?) magic he has to do in order to get rid of it. Could there be any truth to this?

The only experience I have had with copper causing problems was when I recently took on a pool with a copper/ozone/mineral system which we are currently in the process of having removed. The white part of the tile was stained blue and there was a lot of brown stains on the floor of the spa. Cu was 1.3ppb.

So should I run from my one pool that has a gas heater?

 

[JamesW]

Cu was 1.3ppb.

How are you measuring 1.3 ppb?

So should I run from my one pool that has a gas heater?

Heaters are not a problem as long as you know what you're doing.

The acid additions should not be an issue as long as the pH going into the heater is in a good range.

As long as the acid is well distributed, the pH going into the heater should be fine.

 

[JoyfulNoise]

No. As is typically the case, he's misinformed.

When you don't properly care for a pool and allow the pH to crash (which happens a lot with stabilized chlorine pucks and powders) or you do the bone-headed thing of adding chemicals to the skimmer (pool service guys are notorious for throwing chlorine pucks in skimmers), you risk damaging the copper heat exchanger inside the heater. If you follow TFP best practices and keep good control over your water chemistry, then you will never have to worry about corroding a heat exchanger.

It has nothing to do with the aggregate amount of acid needed over the course of a season with a pool but everything to do with how you add it and how much you add at one time. Perhaps his motivation for telling you not to take on swimming pools with heaters was his way of keeping you out of his business....

 

[moore887]

The measurement I took as my example was achieved using a lamotte spintouch.

The service guy in question does some great work with equipment installs/repairs etc but like so many guys I see in the industry, they rely totally on experience and have no formal training or professional qualification or certification. I was very surprised when he told me about the copper staining (if it is indeed that) and more surprised that he had undertaken to carry out the remedy at his own cost.

He did tell me that the customer declined to have a heater bypass valve installed due to cost, which, to me is pennies compared to the price of the heater. If indeed the brown stains were coming from the heater during an aggressive hot start up then not installing a bypass should never have been an option.

Finally, I don't think he is trying to keep me out of his business, in fact, he is trying to give me as many pools in my area as I can possibly take on since he is so busy with his builder. At the rate of new homes and pools being built here and the lack of capable pool service professionals, there's so much work available, I can now seriously reduce my service radius to a few miles.

 

[JamesW]

The measurement I took as my example was achieved using a lamotte spintouch.

1.3 ppm or ppb?

https://lamotte.com/amfile/file/download/file/968/product/358/

 

[moore887]

I guess it's ppm! Thanks James

 

[JoyfulNoise]

The measurement I took as my example was achieved using a lamotte spintouch.

The service guy in question does some great work with equipment installs/repairs etc but like so many guys I see in the industry, they rely totally on experience and have no formal training or professional qualification or certification. I was very surprised when he told me about the copper staining (if it is indeed that) and more surprised that he had undertaken to carry out the remedy at his own cost.

He did tell me that the customer declined to have a heater bypass valve installed due to cost, which, to me is pennies compared to the price of the heater. If indeed the brown stains were coming from the heater during an aggressive hot start up then not installing a bypass should never have been an option.

Finally, I don't think he is trying to keep me out of his business, in fact, he is trying to give me as many pools in my area as I can possibly take on since he is so busy with his builder. At the rate of new homes and pools being built here and the lack of capable pool service professionals, there's so much work available, I can now seriously reduce my service radius to a few miles.

That's all well and good, but he is clearly misinformed about why a heater would present a problem. My pool has a heater, the PB did a "hot start" long ago, I have no by-pass (I will probably add one in the future if/when my filter dies), and I buy 20 Baumè muriatic acid in bulk carriers because it is the one chemical that I add consistently to my pool. I have never had problems with metal staining. My water has always been managed by me following TFP recommended levels. A heater will only cause metal staining issues when the water chemistry is way out of balance. pH is the biggest determining factor for metal corrosion and the pH has to be below 7.0 for significant periods of time for that to be a problem. If this service guy is seeing problems with heaters, then I would suggest his chemical maintenance is to blame.

 

[moore887]

it's copper iron metal staining from coppernickal heat exchanger in gas heaters our electric heaters are all titanium now for this reason Thats what he says on the text but i would love to get a sample of the water

 

[JoyfulNoise]

Cupronickel is a general name for Cu-Ni-Fe alloys. Standard alloys are 90/10 or 70/30 alloys with the 90/10 alloy having the highest thermal conductivity (which is what you want in a heat exchanger). The 90/10 alloy is mostly copper (roughly 90 atomic percent) with the majority balance as Ni. There is typically less than 1 atomic percent Iron in this alloy.

I don’t doubt the person is getting metal staining or that it isn’t coming from the heat exchanger. The cause is poor chemistry maintenance OR trying to do a chemical procedure, like a zero alkalinity treatment where you add lots of acid to the pool, without bypassing the filter first. Even an ascorbic acid treatment should not be performed without bypassing the filter. Under normal operating conditions and with proper chemical management, a heat exchanger will NOT add metals to the water. It’s only when someone isn’t paying attention to the pH or an improper chemical treatment is applied that you can possibly get metal staining. Also, these pools are in Florida and Florida is notorious for having high iron levels in it’s fill water even when it comes from a municipal source. Municipal water suppliers are not required to control iron levels in their water supplies because the EPA does not consider iron a contaminant.

 

[JamesW]

This looks like copper staining.

I don't know the source of copper, but it definitely looks like copper.

during an aggressive hot start up

That means a zero alkalinity treatment, which lowers the pH to 4.5, which will be aggressive to copper.

When dropping the TA to zero or using sulfamic acid, you cannot have the low pH water go through the heater.