I have an Aqua one 980,, ( with a sump tank below and protein skimmer,(about 70 odd gallons in total), i started to cycle the tank about 5 weeks ago,, with some live rock from my local aquarist shop,, about 3 weeks into the cycle i noticed the brown algae,, this has never gone away fully,,, about 2 weeks ago i was advised to introduce my clean up crew,, 6 micro hermits, 2 trocha snails and 2 strom snails,, the stroms eat like pigs,, always moving around the tank, appearing happy, ive since lost one of my trocha snails,, and 4 of my micro hermits since died,, i water change about 10% every 5 days, warming the water first to the temp of the tank, and make sure the salinity is as close to perfect as i can get,, this weekend i introduced 3 small soft corals,, and my first fish,, a damsel,, the poor guy lasted 3 days before swimming upside down,, my soft mushroom coral showed all its colour in the first day,, putting out its small tentacle things to feed, but since then he hasnt showed colour since,, my other small soft coral sticks his tentacles out to feed most days, appearing happy,, i also introduced a nanostream 6045 this weeken as i felt there wasnt enough water movement in the tank,, even though i have to delivery pipes into the top of the tank,, i felt the bottom of the tank wasnt recieving enough water movement,, i added 3 more hermit crabs this weekend also, and within 24 hours 1 had died, and one left his shell,, my water tests have showed 0 amonia, nitrite, and 8.2ph, for a few weeks now,, but i feel i am struggling to get my nitrate to zero,, usually its between zero and 5ppm,, could any of you great people tell me what i am doing wrong? any direction or advice would be greatly appreciated,, i am doing my best to keep the water temp around 25/26 degree,,, and water change every 5 days, about 10%,, was gutted to loose my little fish, and want to get this right, but without rushing things,,, all what i have done so far has been on the recommendation of my aquarist who i feel is very knowledgeable on aquariums,, a big thanks to anyone who reads this,,, its very much appreciated 