hi im new to marines been keeping rifts for 30 months but sick of the fighting and killing so got rid of the fish and added some salt and the bacteria is ok bit of a prob with the ph and ended up with white spot but with a little help from my local shop and a dose of garlic and every think seems to be ok so far i have a copperband a regal a cleaner wrass a black and white perc a pyjama cardinalfish and an orange spot goby my question is can i put an other type of goby in my setup my tank holds 33 gals and has undergraval plus fluval 403 thanks for any help