Avoiding Surface Film in Drop Checker - any tips?

Ray

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31 Oct 2007
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Does anyone else get this? Apparently although surface agitation is enough to keep the surface clear, it still forms in my DC. Once it does I get a nice yellow result 24/7 which is confusing. If I re-fill the DC with air it clears but re-forms quite quickly unless I rinse it out.

How to stop this, should I be soaking it in bleach or boiling it or something?
 

Ray

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31 Oct 2007
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Switzerland
LondonDragon said:
Do you use tank water to create the solution?
No, 4DKh, but I should have been more precise above - the surface film is not on the 4DKh/reagent mix, it is in the funnel where the air pocket in the DC meets the tank water outside.
 

Ed Seeley

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I get it forming whenever I clean a drop checker out or use a new one. I find that after I remove it a couple of times it doesn't form again. Your drop checker's going yellow as the bacterial film (and I'm pretty sure it is a bacterial film that forms) respires CO2 so increases the CO2 concentration as well as reducing the diffusion across the water's surface in the DC.
 

Ray

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Location
Switzerland
Ed Seeley said:
Your drop checker's going yellow as the bacterial film (and I'm pretty sure it is a bacterial film that forms) respires CO2 so increases the CO2 concentration as well as reducing the diffusion across the water's surface in the DC.
I think you are right, but I was wondering, should I be sterilising my DC or something to try to stop it happening - i.e.. is it because I've got biofilm build up on the glass that spreads accross the surface?
 

Ed Seeley

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I've always found it worse when I clean the DC! Just blow off the bacterial film for a few days and it then goes away for me! If that doesn't work then try the sterilisation and see what happens - it won't do any harm.
 
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