Anyone who is using kalk...... How often are you having to clean your return pump? I have a Tunze dc return pump that has to be cleaned about every two months or it will freeze up. I dose kalk through my top off with a Tunze osmolator and Tunze kalk reactor that feeds into my sump (been dosing for just over a year). Should I run the top off into the display vs the sump? Or is this normal? My ALK has tested consistently at 8.0 and calcium at 420 - 440.
Kalk and return pump maintenance
- Thread starter fredfish
- Start date
I am running an Iwaki 70 as the return pump for my 465. I dose Kalk through my ATO, and the ATO line is right next to the pump intake in the sump. Calcium carbonate deposits seem to happen where there is heat, like on heating tubes, impellers on our type pumps, had not noticed it being an issue on the HH hybrid I just replaced with the Iwaki, and the Iwaki is still relatively new on the tank. but I do run twin 500 watt ti heating elements and I have not seen any appreciable CaCO3 deposits on there either.
Do you know what your Ca and Mag levels are? Mine are pretty consistent at 400 and 1300 respectively, which is at the lower end of normal for calcium (380-450) and smack dab in the middle for acceptable mag levels (1250-1350).
Without too much typing, magnesium in solution is what allows calcium to stay in solution and not precipitate out of water, like it would on a heater tube or a pump impeller, like you are experiencing. It is called abiotic precipitation.
If your mag level is low or too low, you could be getting the precipitation on your return pump because of that.
Another or additional explanation could be if your alkalinity level is too high. There is usually a higher calcium level associated the higher your KH goes if levels are in equilibrium. This, and and/or a low mag level could also be contributing to the deposits on your pump.
Not trying to be a chemist, just regurgitating what I know from the Randy Farley series of Reef Chemistry articles.
Do you know what your Ca and Mag levels are? Mine are pretty consistent at 400 and 1300 respectively, which is at the lower end of normal for calcium (380-450) and smack dab in the middle for acceptable mag levels (1250-1350).
Without too much typing, magnesium in solution is what allows calcium to stay in solution and not precipitate out of water, like it would on a heater tube or a pump impeller, like you are experiencing. It is called abiotic precipitation.
If your mag level is low or too low, you could be getting the precipitation on your return pump because of that.
Another or additional explanation could be if your alkalinity level is too high. There is usually a higher calcium level associated the higher your KH goes if levels are in equilibrium. This, and and/or a low mag level could also be contributing to the deposits on your pump.
Not trying to be a chemist, just regurgitating what I know from the Randy Farley series of Reef Chemistry articles.
Thanks for the reply Acroholic........ My mag has been testing at 1400 and calcium is 420, both tested using elos test kits. I gave my return pump, skimmer pump and heaters a vinegar bath today.... Now to see how long before they are due for another. I will also start testing more often so I can see if I am getting any swing in my parameters.
same here,never
Another thought comes to mind. I have a friend that was having to vinegar dip his Iwaki and VorTech pumps every couple weeks to every month. He was dosing 2 part, and turns out he had miscalculated his Ca and Alk dosages and was dosing like 3x what he should have, so he had an excess of CaCO3 available to precipitate on metal heat sources. Once he got on the proper dose, his issues stopped.
When I cleaned the three pumps that are kept in my sump I noticed the only one that had any build up on it was the Tunze dc return pump and only on the rear bushing (bushing froze to impeller shaft). I gave Roger at Tunze a call and explained what I had with the pump. He said that the impeller shaft has a slight taper to it and if the rear bushing is not seated in all the way or the bushing is slightly out of round it can cause it to freeze up prematurely.
