Inline biofilm removal

Troubleshooting
1

How do you guys do it?

I missed my reservoir chiller during my last cycle reset and it was left dormant and packed with leftover nutrient solution. The bladder is sealed and holds approximately 2L with stainless coils throughout to circulate the refrigerant.

I’ve been using a pump to cycle through hot water warm-up / rinse, hot PBW (similar to an alkaline OxiClean) 30 min, hot water rinse 2min, hot citric acid 15min, hot water rinse 2min, cold water rinse 5min then parasitic acid 15min.

I’ve done this about six times today and I’m still getting large membranes of dark biofilm flaking out of the chiller. Do you guys have any other suggestions or adjustments I should make to this process? Should I just keep going at it until the results improve?

I was thinking about dropping the citric acid and the parasitic cycles until the conditions improve. Feel like I’m just wasting good cleaning agents.

Thank you

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2

Just an update, thanks everybody for looking at the original post. I took a break not long after I posted that, started again the next day without the citric or parasitic acid cycles and the biofilm continued to, let’s say “exfoliate” out of the rez chiller.

I spoke to our chem guy at work and he passed me 500ml of our straight caustic cleaner (sodium hydroxide). With his recommendations I mixed into about 2.5 gal of hot water. So slightly more than 5% concentration by volume once mixed in.

Ran it for about 20 minutes, hot rinsed after and nothing was coming out after that. Hot citric acid after that and a cool down followed by a cool parasitic acid cycle and everything is clean as heck.

If you have access to these type of chemicals you definitely want to use proper PPE. Sodium hydroxide is no joke.

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