Can I Keep water in a JOBO?

[Richard Wasserman]

I have a JOBO CPP2 and I would like to keep the water bath full in between developing sessions. I run the JOBO about twice a week and I'm wasting a lot of water every time I drain it and then refill it. Is there something I can add to the water to prevent slime from growing? I know that bleach is not advised; I do have a copper compound fungicide I use in our garden—would this be safe? It's listed as copper diammonia diacetate. Or something else??

[Alan9940]

I fill mine with RO water and do a complete change about every 6 months. I made a styrofoam cover that lays over the water bath area, notched around the lift, and keep the entire unit covered between session. I've never noticed any slime or buildup of any sort working this way. I used to fill/drain with tap water every time I used it, but that's a real PITA.

[Richard Wasserman]

I have RO water, that would be easy!

[Daniel Stone]

Will the RO water be corrosive on the metal heating element? A couple drops of bleach shouldn’t be too bad long term, just enough to keep the bacteria growth problem down.

I’ve used standard tap water, with a little vinegar splashed in to help keep mineral buildup at bay in the past, and never saw any issue with corrosion on the heating elements, it helped keep them nice and clean. Here in my area our water is relatively hard, lots of calcium.

[Richard Wasserman]

I didn't realize that vinegar kills algae, although it certainly makes sense. I also have a lot of vinegar and bleach too.

I was hoping for some single definitive answer, but it appears that there are several methods that should work. I just need to pick one...

[Alan9940]

Will the RO water be corrosive on the metal heating element?

Not sure what would be corrosive causing in RO water, but I can assure you that I've used it for about 15 years in my CPP-2 and my heating element looks as good as the day it was new.

[Jim Michael]

In labs a chemical algaecide is added to the wash tanks. Swimming pool algaecide might be a good alternative.

[Greg]

When I had my CPA-2, I would use double filtered softened well water. Drained and refilled the JOBO on the first of every month. Never had a problem with algae or any kind of buildup. I have heard of using chlorine made for treating hot tubs, but four times more diluted. If I needed to, I'd go the very diluted hot tub chlorine way.

[ic-racer]

About 5 years ago took my CPP2 apart and cleaned the inner tank. Everything was lined with algae and fungus.
I gave it a good cleaning and now I empty it with a turkey baster and sponge at the end of every session and the insides still look and smell like new by keeping it dry between runs.

[nbagno]

Catlabs recommended draining after 3 days.


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[LabRat]

One place I worked temp had one for E6, and left bath filled for months... Looked like a swamp!!! But they kept using it, and eventually it ruined the pump... Took a tech 3 days to take apart unit (not service friendly) to replace (expensive) pump and other parts... Tensions ran high...

If I remember correctly, it didn't have a drain, so difficult to drain... You can consider adding one if possible...

Steve K

[Greg]

If I remember correctly, it didn't have a drain, so difficult to drain... You can consider adding one if possible...

Steve K

Mine had a drain. Wasn't OEM for sure. I always thought it was a replacement drain valve, but then I guess it was added on by the previous owner. Looked to be a simple thing to add on.

[koraks]

I've had my CPE2 for something like 5 years now. I think I drained it once. During prolonged periods of darkroom absence, the water level drops to perhaps 1/3 its original volume due to evaporation. The water is plain tap water with no additives - apart from the inevitable chemical spills. I don't need to tell you what the water looks like...it's pure filth, obviously. But it doesn't stink, and it's come to the point where mosquitoes cannot breed in it anymore either. The Jobo, of course, continues to work perfectly. In a few months we'll move and then I'll clean it properly.

[Lars Holte]

I have had a Jobo ATL-1500 for six-seven years now, and I would never contemplate leaving water in it for more than a couple of days or a week tops. I mostly develop black and white, but I have also used it to develop E-6 and C-41, and I run the cleaning program regularly with a small amount of granular citric acid (that is what Jobo Processor Clean is) in the cleaning water. I also let it stand with the lids on the chemical containers open and the top lid open.
It looks better inside now than when I got it. In fact it looks almost like new. Such a machine is too expensive to replace, so I think the small effort well spent.

[Fred L]

If I expect to run film, I'll keep the CPP-2 filled with water for a couple of weeks. if It's going to be more than a month, I usually drain it. Every now and then I'll take the trough off and deep clean. fwiw, I'm using city tap, unsoftened.

[Peter De Smidt]

"Will the RO water be corrosive on the metal heating element?"

Yes.

[Richard Wasserman]

I was hoping for some sort of consensus on my question, but should have known better than to expect one... Silly me!

I did vast research (about 2 minutes on google) and learned that algae prefers to grow in an environment with a PH of about 7-7.4—my tap water is 7.9. I am going to try adding a bit of Citric Acid, which I am assuming is harmless to the JOBO, to the tank. I'll keep an eye on it and keep my fingers crossed. It just feels so wasteful to dump gallons of water every time I run the processor.

Thanks everyone

[Michael R]

And...here’s another opinion in case you didn’t have enough of them already :) ...I wouldn’t recommend citric acid for this. Citric acid supports the growth of all sorts of gooey life, slime etc. This is why plain citric acid stop baths (for example) don’t usually keep for very long. Ilford’s Ilfostop (citric acid) includes a biocide to help preserve it.

You’re probably better off using benzoic acid/sodium benzoate, which is fairly innocuous.

Or perhaps a small amount of bleach as others have suggested.

Including a chelating agent like calgon or one of the other better ones might also help prevent calcium and other metal deposits depending on water quality.

Someone ought to formulate and market a “long life tempering bath solution for Jobo processors” :D




I was hoping for some sort of consensus on my question, but should have known better than to expect one... Silly me!

I did vast research (about 2 minutes on google) and learned that algae prefers to grow in an environment with a PH of about 7-7.4—my tap water is 7.9. I am going to try adding a bit of Citric Acid, which I am assuming is harmless to the JOBO, to the tank. I'll keep an eye on it and keep my fingers crossed. It just feels so wasteful to dump gallons of water every time I run the processor.

Thanks everyone

[Richard Wasserman]

And...here’s another opinion in case you didn’t have enough of them already :) ...I wouldn’t recommend citric acid for this. Citric acid supports the growth of all sorts of gooey life, slime etc. This is why plain citric acid stop baths (for example) don’t usually keep for very long. Ilford’s Ilfostop (citric acid) includes a biocide to help preserve it.

You’re probably better off using benzoic acid/sodium benzoate, which is fairly innocuous.

Or perhaps a small amount of bleach as others have suggested.

Including a chelating agent like calgon or one of the other better ones might also help prevent calcium and other metal deposits depending on water quality.

Someone ought to formulate and market a “long life tempering bath solution for Jobo processors” :D

I'm going to cry...

Maybe I should should simply drain the JOBO in between processing runs and call it done. This is much more complicated than I expected!

[Drew Wiley]

Scum will build up. But the easiest way to control microbes and water mold for awhile is to throw a capful of Listerine in the water. Make sure it's the original formula or generic equivalent containing Thymol.

[lassethomas]

I tried in the beginning to keep the water but was never comfortable with all the guck. Just can't be good for the pump and heater. Tried some pool chemical that made it better, but then wasn't comfortable with the biocide angle.
Mine has no drain so I got a siphon.

219609

I only keep the water for at most 2-3 days now.