As mentioned above, Aptasia is quite tricky to get rid off. I had a battle with it couple of months ago. I tried everything (i.e. juice, paste) i even ended up removing rocks that have aptasia, but they're always "everywhere". Did tried peppermint shrimp too. Yes they "disappeared" especially when they are small.Aptasia will never go away without braking your tank down.
Aptasia will live in your hoses, sump, overflows, just about anywhere. They will always exist in your tank but u can eliminate them from the display tank.
You can control it in several ways, the fastest and nicest way is by getting a copperband butterfly or a matted filefish.
Since u hardly have corals I would go with either fish, if u plan to add corals go with the butterfly.
U can try alternative ways but u will waste your money and time. U can try juices, paste, zapping, trust me, they will win and u will lose.
Add a natural predator fish and in a month they will be gone.
The peppermind shrimp work but shrimp don't eat the adult aptasia and shrimp prefer waiting for u to feed the tank rather than eating nasty anemones. Shrimp "disappear" as well, u could end up spending more on shrimp then on copperband fish.
Chose your weapon and good luck