I have a wicking system to water succulents while away for extended period of time. How do I prevent mold in reservoirs without hurting plants?

A medium's ability to work when wick watering is employed depends in very large [part on the size of the soil particles, which is what drives it's ability to pull water upward (capillarity). If you're using a wicking system with enough capillarity for the system to work, it's highly likely the medium is not well-suited to growing succulents.
Example: Both the following media are well-suited to growing succulents because of their high porosity and reduced ability to hold excess (perched) water.


Unfortunately, because of their limited capillarity, they are not good candidates for wick watering. You could use a wick with a high degree of efficacy to DRAIN excess water from pots, but not to pull water up from a reservoir into the medium.

You can easily prevent mold and other forms of unwanted growth in reservoirs through use of a UV light and/or by adding H2O2 (hydrogen peroxide) to the water in the reservoir. H2O2 is a powerful oxidase because of the O- free oxygen radicals it contains, and will attack the first organic molecule it comes in contact with.

Al

Thank you for great info!!

Tapla makes a good point. Hydrogen peroxide should work well. It's actually good for plants in very small doses for many things. If you search the internet for 'using hydrogen peroxide on houseplants' you will find a lot of info that will help you. Best wishes.
Debbie

Thanks Debbie!!

Hello and Welcome kbjex!
I hope you don't mind a couple of questions.
What sort of succulents are you growing, and how long will you be gone?
I'm generally agreeing with Al, a good succulent soil will not be good at wicking up water. Also, most succulents like a bit of a dry period between waterings.
But, it can depend on what you're watering.
Water here has a lot of dissolved minerals. I've found that any sort of bottom watering will eventually kill off my plants from excess mineral accumulation in the soil.
I have used wicks to "unwater" plants that were being overwatered by well-meaning visitors. They work great for that.

I have several different plants. What do you suggest instead of wicking?

What are the plants and what kind of interval are we talking about. A week, month, more?

Al

Not sure exactly what they are but are all succulents. Will be gone 2 to 3 months

Some might not even blink, untended for 3 months. Or, not much problem.
If we saw a picture, we might be more specific on advice.

kbjex,
Could you post pictures? That would be very helpful, don't worry about their names.
I think it might be difficult to keep any houseplants alive with no care for 2 or 3 months. It would take an elaborate wick watering system to keep them watered that long, and that might not work too well with succulents anyhow.
Can you have someone stop by and take care of them every week or two? In my area, dog sitters can often be hired for this, and rates aren't bad.
Or do you have someone you could leave them with while you're gone?
Again, a lot depends on the type of succulent, please post pictures if you can.