Nielsen reactor makes a bubbly film

[Osama]

I have been using my Nielsen reactor for 6 months & pretty much likes the reactor & like not having to manually mix the kalk. Yesterday & for the first time I am seeing a white clowdy film in the sump where the Nielsen kalk drips in. Around that area thee is a white bubble of white scum that I easily skim & remove. I checked the output from the reactor at ph =12.08 my tank dKH=7. I am planning to replace the powder in the reactor this weekend BUT I am interested in knowing what do you think is happening Could there be something else I am overlooking. Everything in the main tank looks good. tank pH is at 8.25 & drops to 8-8.1 at night.

 

[ChrisRD]

Are you dripping into a high flow area of the sump?
Is the kalk completely dissolved in the effluent that is coming out of your reactor, or do you have some suspended kalk solids in it?
What brand of kalkwasser (or pickling lime) are you using?
Either way, I wouldn't be too concerned, but I'm guessing the problem has to do with one (or all) of the things above.

 

[ChrisRD]

Another thought just came to mind too...

How long has it been since you recharged the reactor?

 

[Osama]

Chris: I added a week ago one and a half cupfull of fresh Kalk. I use I believe kalk from two little fishies. Have been for 6 months with no previous negative observation. Could be the kalk has gone bad but the pH rdgs indicate kalk should be OK at pH above 12. I am dripping kalk in a low flow area as greenery has grown & slowed circulation acrross sump. Fluid in reactor looks quite clear at the outlet of the reactor. I will move the drippping to a higher circulation afrea & see what happens. Any other considerations/ideas about the possible cause are greatly appreciated. Thanks Chris

 

[Anonymous]

No matter how careful you are, there will always be a portion of the kalk that went "bad" because of contact with air. But for most situation, this is not a problem since as long as the kalk solution is saturated (definitely in the case of kalk reactor, unless the amount of "good" kalk is not enough to saturate the water column in the reactor). The pH and alk reading will show a saturated kalk mixture dispite a small amount of "bad" kalk, so it is not useful way to confirm it. However, as I say above, there is nothing to be concerned about as long as the solution is saturated (as pH measurement shows), but I was just telling you that the pH test is not good for monitoring how "bad" the kalk had became.

Anyway, there is some harmless impurity in most kalk mix, so what you observed may not be something to be of concern. For the interested, there is an article in AAOM about detoriation of kalk that you may want to check out.

 

[Joey French]

The idea of kalk going "bad" has been refuted of late, here's the link for further reading...
http://reefkeeping.com/issues/2003-05/r ... /index.htm
Joey

 

[Anonymous]

Thanx. The article I mentioned above is in Reefkeeping, not AAOM.

 

[Osama]

Thanks David & Joey; Sounds from all of the input I got and the fact that things are very stable in the tank that by just continuing to watch things & possibly move the kalk effluent to an area with a bit more flow will be all that is needed.
Thanks to you all above.