Cross Contamination - Life Will Find A Way

[DeepBrew]

I presently have three tanks set up, 75G reef in the house, a 40B in a separate building I call the Brewdio, and a 20L frag tank also in the Brewdio. Naturally I have a big stack of old salt buckets that get used for various things and I haven't paid a lot of attention to making sure they aren't moved between tanks without thorough cleaning in the past. I think that's about to change.

I did a lot of clean up last Sunday afternoon and when I was done I rinsed all of the buckets with tap water, wiped anything I could see out and set them unstacked on the Brewdio floor to dry. Some friends came over Thursday to hang out so I stacked the buckets, which had been drying 4 days to make room. This morning I grabbed a couple buckets from the stack and noticed some purple spots in the bucket which had another one stacked on it. They were tiny, 1mm or so spots. I know they were not there when I stacked the buckets so I decided to take a closer look. I managed to soak a spot in R/O water and get a little piece of it on a microscope slide. Pardon the bubbles, my technique is not the best:



That looks like a hodgepodge of algae, let's take a closer look:


I'm not very good at ID yet but I think there's some spirulina and cyano among other stuff in there.

Here's an interesting thing in the top right, I have no idea what it is:


This is the same spot focused deeper:


More spirulina here, not sure what the round brownish critters are:


I'll definitely be giving this bucket a more thorough cleaning before using it again.

It seems like there's lots of stories on R2R that go some like "I had a problem, treated and it went away. A month later it came back." I wonder how often that happens because we don't thoroughly clean equipment between maintenance uses and reintroduce nuisance organisms.

Somebody please tell me I'm wrong so I don't have to clean everything again. :)

 

[Diesel]

Thanks for bring this up.
I use two orange buckets for old salt water and only blue for new salt water.
In that case I don't have to worry about this.
But yes a big problem is that many hobbyist don't think about this.

 

[DeepBrew]

Thanks for bring this up.
I use two orange buckets for old salt water and only blue for new salt water.
In that case I don't have to worry about this.
But yes a big problem is that many hobbyist don't think about this.

I typically make enough to do changes for all three tanks in a 32 gallon brute. I have a submersible pond pump with some vinyl hose that I use to pump water from the can into the tanks. I've never thought about this as a potential way to spread disease or nuisance critters between tanks but now I'm wondering if it is. No doubt some water from the first tank gets on the end of the vinyl hose. The hose gets dropped back into the brute with the rest of the "clean" water. Then it's on to the next tank with the same hose and "clean" water which now has at least a few drops of tank water in it.

The white buckets are generally only used for "dirty" water, but haven't paid that much attention in the past. I'm sure there have been times when a dirty bucket from one tank was used for clean stuff in a different tank with just a quick rinse.

I suppose I have enough buckets and tubing around to do water changes without using any common equipment between tanks. I'm not sure how I'm going to deal with using a common clean water and pump set up though.