Welcome to Jarek's Underwater Life.
Interested in fishkeeping? Want to have an aquarium? Or just looking for something to read?
The objective of this site is demonstrating my experience with fishkeeping.
Don't know where to start? You can learn what to consider when you want to create your own aquarium.
Frequently out of home? You can learn how to automate your aquarium.
Bored by the on/off light? You can learn how easy it is to build your own energy efficient light that will imitate daylight from the sunrise to the sunset.
3/1/2026
AquaSky unit completion
AquaSky is a fully programmable unit designed for controlling LED lighting and aquarium technologies. It offers precise PWM control of four LED channels, two auxiliary outputs, Bluetooth communication, automatic time management, and advanced protection features. The current version delivers stable software, low power consumption, and a range of safety mechanisms that ensure reliable long‑term operation.
16/2/2025
Innovation of Juwel aquarium light
The LED profiles and connectors of the old light were placed under the cover, i.e. in permanent humidity. This resulted in the degradation of the fans and connectors. It was necessary to design a new light. The article describes the innovation of the light, where the original Juwel ramp is completely replaced.
13/9/2024
New fish and changes in the aquarium
I bought new fish: Angelfish and Cardinal tetras. I changed the aquarium's look.
29/4/2024
Retirement of TC420 and time-controlled outlet for CO2
The AquaSky controller box fabrication. Decommission of the TC420 and time-controlled outlet for CO2 and their replacement by the AquaSky and proper outlet for CO2.
