Help With My Marine Setup

[cruise82]

hello all i need some real help i have been running a marine tank for a few years now and decided to get a larger one so went for the orca tl-550 its been set up now for 8 weeks with 30kg of fiji live and 30 kg of live sand have 5 red leg crabs a electric blue led a red fire shrimp 4 turbo snails and 2 clowns all from my old tank but i seem to have all this brown algue everywhere i have been told this is common in new tanks but have never had this problem is there something i can put in the tank to clear is up and get rid of the Silica fast when i first filled the tank i used tap water to mix the salt stupin i know should of known better i now use seapure sea water also my crabs are looking sick and i lost the blue leg 2 days ago i have checked the levels and all are very good spot on apart from the kh witch is 15 this is high i no could this be the problem with the crabs and how can i sort this out i really need your help before its too late and i loose more of the little critters

 

[seffieuk]

Sounds like normal diatoms to me - have you got a picture?

Seffie x

 

[cruise82]

Sounds like normal diatoms to me - have you got a picture?
thank you for getting back to me yes thats what it sounds like from what i have seen wiuth other tank s how can i get rid of it have tried every thing i keep cleaning it and get up the next day and its back somtime worse than before need help all levels are good light is not on for more than 7 hours a day
Seffie x