Alge question???

[Holmez221b]

My friend was moving so It was a rush to set up a tank in my house... He gave me a couple corals and 3 fish.. The sand was seeded with sand from his tank and I used cured live rock.. I had a huge diatom bloom within 4 days of setting up the tank.. It has setteled since then but now I notice some red alge..Does this mean the cycle is coming to an end?? Also should I be doing water changes to avoid an amonia spike??

Thanks for all your help