Metal shavings buildup on dosing pump

[ReefEnabler]

Hello,

I currently have a Dosing station with 3 dosing pumps. So far I've only used 1 for my auto topoff.

I just noticed that a powder of metal shavings is building up around the center of the white plastic housing. Thinking maybe the bearings in this pump are going, I switched to another pump, one that has never been used.

After a day or two I saw the metal shavings again.

Is this normal, or is something wrong? I'm worried these shavings might get into my sump and contaminate the water with metals. Has anybody heard of this before?

My usage is nothing special... maybe 1-2 gallons per day.

 

[ReefEnabler]

Ok posted in your 'new and "improved" support forums'

BTW.... making us go through registration on a site where everything is in German is just cruel!!

 

[AQD_ottawa]

Hiya

The tolerance on the shafts to the pump are extremely tight and as they bed in you will get some wear in, this is normal and a sure sign of high engineering of the two parts. You will also get some black from the pump motor, this is the carbon brushes bedding in.

There are NO metal bearing in the unit as can be shown here so do not worry. However if you are still concerned please follow the service guidelines

http://www.aquariumcomputer.com/Forum/showthread.php?t=28

 

[ReefEnabler]

Ok great, thanks!

One followup...

Step 5:
Continue to remove the rollers and peri tubing taking care not to move the two black clips on the tube as these set the internal tube distance.

I've noticed that the tubes coming out of my pump have "walked" quite a bit.... it used to be an equal length of tube before each clear plastic adapter...... but now theres maybe 1" of line on one side and 2" on the other... so the tubes seem to be slowly moving to one side. Is this also normal?

 

[AQD_ottawa]

Follow the service guide and you will see the two positioners you can see if one positioner has come out of location but this would be a first.

The other thing that could cause this is a pipe blockage that will also explain the wear on the shaft as the pump slips and strains, this could be the reason for your wear in showing and also the pipe running.

Blockages are not always easy to find as the pipe does not have to be fully blocked.

I would look at possibly replacing the tubing, we do have it as a spare part. tubes should be replaced every 6 months or less if dosing minerals and are pennies really to replace.

 

[ReefEnabler]

ok I will try the cleaning later. but just FYI I am using RO water through it. But water is being pushed through a Kalk-reactor. Could this back pressure be an issue?

 

[AQD_ottawa]

Yes and also the kalk will build up in the pipe 100% for sure.

There is your issue.

Resolution

Maintain the pump assy on a monthly basis and replace tubing every 6 months or less if build up occurs sooner, you can get this direct from us I would get enough for 1 year though to save on postage.

Kalk acts like Fat in a vein basically.

 

[ReefEnabler]

Well the kalk is AFTER the dosing pump, and then theres only 10" of tubing from the reactor to my sump... and I regularly clean out the tube exiting the reactor.

Are you saying the kalk will work its way backwards up the tube, or the restriction will cause wear even if its at the end?

 

[AQD_ottawa]

Yes the restriction will cause pressure build up in the pump and then onto the motor, Peri pumps must work without back pressure otherwise the pumps can wear rapidly, this goes with any peri pump and why they work best at zero head

I would fit a non return valve for starters, and then make sure the tubing within and after the pump is always free from build up.

You will have trouble free long operation times then with no issues

 

[stunreefer]

Re: Metal shavings buildup on dosing pump

by ReefEnabler
Is this normal, or is something wrong? I'm worried these shavings might get into my sump and contaminate the water with metals. Has anybody heard of this before?

Hello Reef Enabler,

I noticed the same thing on one of my Dosing Pumps that I was using for ATO, and as Michael explained it does stop (or reduce) over time. However, IME these pumps should be used only for dosing and not ATO as ATO uses the pumps much, much more causing them to wear out much sooner. I got just short of a year from one of my Dosing Pumps I was using for ATO. It still works, but its perfomance is very slow compared to the other two pumps I only use for Ca/Alk additions... just my 2 cents

 

[AQD_ottawa]

You can use peri pumps for dosing minerals BUT as shown the wear on the unit will be much higher as you are shifting or pushing solids held in suspension.

This is with ANY doser you buy not just GHL, we have to remember where dosers came from, their original intended use was for dosing chemicals and also drugs in hospitals, since their leap over to the aquatic industry the pump designs have not changed and any good manufacturer sources the pumps and motors from the same source as the chemists or hospitals as they are the most reliable, but of course in labs and hospitals they are not pumping solids.

So to overcome this if using the doser for this purpose always service the unit regularly and make sure no build up in the pipes occurs.

Hope that helps with a better level of understanding what dosers original useages were.