I have been keeping a Biocube 32 LED for the past 2.5 years. I love it. It is a great intro to the hobby while keeping costs in check, somewhat.
Here are a few of my recommendations/random thoughts:
- I used dry rock with live sand to seed my system. The cycle took about 2-3 weeks.
- I used Dr. Tim's Ammonia during the cycle. It is superior to the rotten food method because you know exactly how much ammonia is going into your tank.
- The stock return pump is okay at first, but I recommend adding another pump or upgrading the return pump to get better flow. It will help your corals and keep your tank clean.
- Slowly, very slowly add fish and corals to your tank. This will allow you time to observe any changes to your system and adapt as needed.
- A regular weekly 5 gallon water change will solve most if not all of your problems for the first year+.
- I used RO water from my grocery store for the first couple of years before purchasing a BRS system. This purchase was driven primarily due to COVID shutting down my grocery store's machine. I have been happy with the BRS system, but I don't think you need it day one. You could also buy RO/DI from your local fish store as an option. My LFS charges $.31/gallon for just the water.
- Start off with some soft corals (e.g., a toadstool, ricordea mushrooms and some zoas/palys). Once you have coraline algae growing, you can add LPS, such as blastos and/or hammer corals. I have yet to find an LPS/soft coral that I cannot grow in my Biocube. The stock lights get the job done.
- I do not use an ATO. I check the water level every night when I feed my fish and add water as needed. Some nights I do not need to add any water. Caveat - My tank is in the basement which is the opposite of a dry environment. If you live in a desert or something, your mileage may vary.
- Throw out the Biocube filter cartridge. It is really overpriced for what it is, activated carbon and filter floss. Instead purchase some carbon and media bag(s) from BRS and filter floss from inTank. I would also recommend purchasing a media basket from inTank.
- I used the ATI testing kit for my first year+. It is not great, but it is sufficient for what you will have in your tank initially.
- As you you SLOWLY add LPS corals, you will hit a point where they start to look a little sad. This is your queue to start thinking about testing and adding Alk and Calc to your system. I now add about 5 ml of Alk and Calc each night, and I have a lot of LPS in the my tank. My magnesium is still handled by the water changes.
- I purchased a Tunze nano skimmer early on and have been happy with it. I don't think it is completely necessary right out of the gate, but it does give you a little bit of buffer for keeping your tank parameters in order.
- I know this seems crazy, but you should really consider setting up a 10 gallon quarantine tank, too. I have struggled with some fish deaths that I contribute almost fully to my initially poor quarantine and social acclimation practices. This does not need to be anything elaborate: 10g tank, heater, hang-on-back filter, a desk lamp on a timer, and PVC pipes.
- Once you hit a critical mass of fish/corals in your tank, you should consider adding a backup battery/return pump to your system. I went with an Innovative Marine DC pump + IceCap battery combo. These are reasonably priced and get the job done for 24 hour power outages.
Good luck starting off! It is a fantastic hobby, but please understand it will demand some of your time and money.