Big diatom bloom

Hey guys, I'm having a really big diatom bloom issue. I just got some silicate removing media yesterday and in the past 3 days have done 7 gallons of water change in my 20 gallon. The first change was 3 gallons and I got half of the bloom out. Then the next day (yesterday) I did a 4 gallon change and did the entire sand bed. I blew off all the rocks before hand and let everything clear up before doing the water change. Today, although not as bad as it has been the diatoms are already taking over again. I believe the silicates are coming from my rock.



ammonia = 0

nitrite = 0

nitrate = 0

phosphate = 0

Calcium = 480

pH = 7.8-8.0

Alk = 9.5

mag = 1400

temp = 77.5-78.5 (controlled)



I have,now, only 1 hermit that I believe they feed on the diatoms. My other hermit died yesterday morning, idk why. All corals look really healthy and fully extended. Are they any other methods to removing or eliminating this problem besides water changes? Will this media work well? Seachem SeaGel. It removes silicates, phosphates, heavy metals and acids. I just added this stuff yesterday night.