Most people replace the stock return pump with
Cobalt Aquatics MJ Multi-Purpose Powerhead/Pump it increases the turnover rate to 295 GPH from 265 GPH. As mentioned before flow is very important in a reeftank. You would still want to supplement this with the circulation pumps we discussed before. The other big upgrade that I would probably do before the return pump is get rid of the bioballs and false floors in the back chambers and replace it with the InTank media basket,
Coralife Biocube 29 Media Basket with the water director. this is a nice addition allowing you to place chemi-pure, purigen, and some filter floss on the shelves to increase water contact with your chemical filtration. I also recommend getting the fish saver
BioCube 29 Fish Saver this one is for the oceanice version of the biocube, but yours is probably a Coralife version if it is new so look for one for that one. Believe it or not fish can and will get through that gap and into your back chamber section. I believe those are some great upgrades for you to start with. No need to overcomplicate things. In the future when you start keeping coral mainly SPS you will want to look into upgrading the lights. My guess is you have the Compact PC set-up with the little led strips. FWIW don't waste money on the led strips they make for that tank they are not worth it more for aesthetics than growing coral. If you decide you absolutely want to add those strips I have some I will sell you cheaper than you can buy barely used. Also keep an eye on your running temps. I had heat problems in the summer time for mine which is the main reason I upgraded my lights to led's. The stock lights are good enough for most soft coral and some lps. I have seen some support SPS. If you have issues with your tank running warm I can help you solve that fairly easily. Well that is more than enough for you right now just some thoughts. Good luck and any more questions feel free to ask.
Thanks for any advise
