Pumps Seize - Caused by Dosing?

[nickkohrn]

I have a Waterbox 100.3, which has a sump chamber that has just enough room to fit my skimmer, MarinePure block, a Maxi-Jet 400 for circulation, and a pump to feed my UV sterilizer and GFO reactor. Unfortunately, I just had a second pump seize last night, which is the pump used to feed the UV sterilizer and GFO reactor. After a night of running in a mixture of water and citric acid, the pump continues to seize. This is the second pump to seize within three months, so I need to go purchase two tonight so that I can have another backup. I haven't noticed a buildup of precipitation or the pump that would cause me to believe that it's happening as a result of dosing, but I know that the chamber is small, and it's likely that dosing in the same chamber is causing it. As you can see, my return chamber is covered with precipitation, and that will be cleaned this weekend as I have a spare return pump to use during maintenance.

I use the Maxi-Jet 400 to circulate water under the dosing lines so that it can be dispersed quickly. At the moment, I am only dosing 12.5mL of alkalinity daily, and I am testing this week to determine how much calcium to start dosing. I keep alkalinity at 9dKH, calcium is around 415ppm, and magnesium is around 1250ppm.

Before I start dosing calcium, I want to figure out how to reduce equipment failures. Below are photos that show my sump configuration. I apologize for the poor quality, but it is difficult to get decent photos due to the small space.

The dosing lines are at the back of the sump, and the Maxi-Jet 400 is pointed toward the rear of the sump. Just between the skimmer and Maxi-Jet 400 is where the seized pump sat, which connected to the dangling tube in the return section.

My sump is filled with all sorts of growth from sponges and other lifeforms. A deep cleaning is necessary this weekend to remove the buildup in all chambers.

I utilize a carbon dioxide scrubber, so will the high pH (8.2-8.4) cause more precipitation than lower pH levels? I prefer to keep the scrubber as I have noticed much more growth than prior to its addition, but I would rather keep equipment working without having to soak everything in a cleaning solution every week.

Is there a better location at which to place my dosing lines? I thought about placing them before my filter socks, but I don't want my skimmer's pump to seize. I don't like having them in the return section because I don't want the precipitation to cause issues with my automatic top-off sensors and return pump since those items are critical pieces of equipment that my system relies on.

I will appreciate any advice, recommendation, experience, and anything else that can help me prevent equipment failures with regard to issues caused by dosing.

 

[mmatt]

I'll be honest I didn't read your whole detailed posted. I just have a really short attention span. Lol.

But I will answer your title. Yes it can. I had the same issue. A few years ago my newbie mistake was to dump my dose lines (cal,alk,mag)in my return pump section. Oops . My though process was it would mix better. How ever over time it hardens. And in my return pump since im dumping raw product right in it. Seized my return. Pulled the pump apart and had calcium build up all over the magnet and internally in the pump. Second pump I moved my dosing lines to another chamber and make an effort to take my pump apart and inspect and service. So move dosing lines as far away from your return as possible. And pull your pumps apart and clean them on occasion.

My new build I have a cal reactor. But haven't hooked it up yet since the tank is a few weeks new and I don't know what I'm doing when it comes to calcium reactors. Lol

Hope that helps. Cheers

 

[Water Dog]

Unless I missed it, what was the make and model of the pump that failed?

 

[nickkohrn]

I'll be honest I didn't read your whole detailed posted. I just have a really short attention span. Lol.

But I will answer your title. Yes it can. I had the same issue. A few years ago my newbie mistake was to dump my dose lines (cal,alk,mag)in my return pump section. Oops . My though process was it would mix better. How ever over time it hardens. And in my return pump since im dumping raw product right in it. Seized my return. Pulled the pump apart and had calcium build up all over the magnet and internally in the pump. Second pump I moved my dosing lines to another chamber and make an effort to take my pump apart and inspect and service. So move dosing lines as far away from your return as possible. And pull your pumps apart and clean them on occasion.

My new build I have a cal reactor. But haven't hooked it up yet since the tank is a few weeks new and I don't know what I'm doing when it comes to calcium reactors. Lol

Hope that helps. Cheers

Yeah, my return pump needs to be cleaned. That chamber is covered in precipitant. I'm glad that I picked up a second COR-15 for my mixing container because I can use it as a replacement during maintenance and as a replacement, if needed.

Unless I missed it, what was the make and model of the pump that failed?

The first pump failed a little over one month ago, and it was a Sicce Syncra 1.5. The pump that seized last night is an EcoPlus, but I don't know what the model identifier is.

 

[nickkohrn]

Could restriction of the pump cause seizing?

I ask because my UV sterilizer and GFO reactor are plumbed inline due to space limitations. I have had to restrict the pump's flow down to ~50gph from its stated rate of ~350gph to keep my GFO from tumbling violently.

 

[mmatt]

Possible but I don't think so. My mind is set on the dosing. Just from my past experience.

 

[rockskimmerflow]

@nickkohrn It's very possible. I have a customer who's prior service company had burned up 2 iwaki pumps in the span of 6 months by overdosing 2 part into the return intake and caking that area and the pump volute with precipitate. I prefer to dose in the dump chamber from the drains and use a powerhead or other pump pointing directly at the point where the doser inputs to disperse the liquid immediately. There should not be tons of white caked on precipitate forming in any chamber of your sump so you're definitely correct in noticing it and recognizing it could cause issues. The heat generated when the friction of a pump shaft and rotor bearings increases from calcium carbonate precipitate can absolutely kill a pump over time. Best of luck!!