Tank problems

[Guest D33rex]

Maybe someone out there can help me with this.

I keep getting a white film on the top of my water in my 40g tank.  I have plenty of circulation, a sump, a 15 gallon bucket and doser that I use with kalk, a reef devil skimmer which pumps out gunk very proficiently.  So whats the deal?  Am I adding to much kalk?...I only use about a teaspoon per 4-5 gallons.  I thought I may be mixing too much top-off water with kalk because I only have to refill it about every 2 weeks....and maybe that causes the film for some reason?  Should I have a pump in the top-off bucket for circulation?... or just mix less?  ...

[michaelg]

What is aggitating the surface of the water?   White film sounds weird- 1 teaspoon for that much is not much at all.  Where are you drawing the water from?  It shouldn't be on the bottom of the topoff container, and the top should have a kalk scum that you don't want either.

[flowerseller]

Assuming you are using a surface skimmer (over flow box) I would increase the ripple effect on the waters surface.

Easily accompllished by directing a powerhead at a slight angle upward.

[Guest D33rex]

So mikeg u are saying that you want the suction tube in the top-off bucket somewhere in the middle of the bucket?...you may be right there is a lot of residue that sits on the bottom of the container...

    As for circulation at the water's surface I think i have plenty...it just kind of pushes the film around.  

Thanks both very much for your input...Ill let you know if it clears up.

[flowerseller]

I have never heard of kalkwasser causing a film on the top of a tank, regardless if you are sucking the milky kalk or not. I do it all the time. That film is caused by the bio load in the tank and not enough surface aggitation. This reduces the gas/oxygen exchange tremendously and compounds the problem.

You should be able to remedy the situation by simply increasing the water aggitation at the surface, maybe even directing the surface flow toward the siphon box/surface skimmer.

[craby]

Yeah, what Chip said. I had the same problem, and pointing a ph slightly up to ripple the top of water fixed it.