hi, im in need of a little or maybe alot of help, started up a reef tank just over 6 weeks ago and pretty much went to our few local aquarium shops and relied on them to help us start out with what we needed, (maybe our first mistake) as now all I have done is google as much as I can and found out alot more than they told us. Had brown algae removed that, my tang had ich treated that. We were patient before adding anything, everything was going good until about 2 weeks ago, before that we had made quite a few mistakes, wasn't told we shouldn't use tap water, now using RODI water, about 2 weeks ago realised we had the wrong light (have a feeling this mistake was a biggie) as things have gone down hill since then, didn't know we needed to frequently test the water, didn't know how frequently we needed to do water changes, yes i feel like an idiot so please be nice... started testing had really high ammonia, nitrite and nitrate and slightly high pH. Got advice to lower all this with nitrate remover and water changes ( gradually getting lower day by day. Have lowered intensity of light as advised, have reduced feeding... Have got green algae, brown water and really unsure as to what to do next. Have a 150ltr tank with sump and need help please!!!!