Hello everyone,

I finally got my Eheim 2026 filter and Vecton UV Sterilizer 15W. My fish tank is 40 g and perfectly cycled.

I understand that it will take some time for the new bio-substrate in the filter to be colonized with bactetia. I am thinking if I start using UV Sterilizer right away it may affect bacteria colonization. To get inside of the Eheim filter bacteria has to travel through the water to sattle on the substrate. If I run UV it will reduce the number of bacteria that will rich the substrate, therefore making the time of complete colonization much longer.

Do you think you agreee with my thoughts? How long should I run the Eheim filter before starting to use UV Sterilizer???

I know basically nothing about the abilities of a particular UV sterilizer, but it would seem to me that if you ran the system for about a week with no sterilizer, it should add a very good starter colony in the filter. From then on, even if the UV removed any bacteria from the water flow, it would have its own base to continue growing a substantial colony.

Can you simply seed the new filter with media from the working filter? Trade some ceramic or sintered glass pieces between them? I pull some of the ceramic from my Eheim anytime I need a good start on a filter. I just replace it with pieces that I have boiled out from another project. I keep extra around for just that purpose.

If you have floss or sponge, it is easy enough to tuck a piece into the Eheim baskets.

This way, you could start the UV unit immediately!

i also recently uped to a 2026. i'm giving the thing a month to settle in before turning on the light.

thanks for ur suggestions

In addition to following Daryl's suggestion, do not turn on the sterilizer until the tank is completely cycled.