This was my situation in my 30 gallon, having a shrimp and goby. The sand will be fine. You'll just need to be proactive with keeping the sandbed turned while UV is in operation. Since the tank is small the 55w jebao may be oversized though can be utilized if space is available. There is always the 9w coralife turbo twist, or some of us had some luck with the green killing machine from petsmart. However, the uv will need to ran for quite some time. Going though a dino bloom is almost like having a reset switch on the tank maturing.
Remove the chemipure blue and phosban.
Get Stump remover from hardware store for nitrates. KNO3
Get a small bottle of seachem phosphorus for phosphates.
You'll need to dose nutrients back into the system to feed dino competitors. Target 0.05-0.10 - po4 and 5-10 No3