too litttle nutrients? and a pocillipora question

[Seraphim]

is there such a thing as too little nutrients? I test everyday....0 organcs with api tests. ca 450 dkh 10.3ish ph 8.2 sg 1.025 temp 77. I dose C/B everyday kent essential elements once a week kent strontim every 4 days. and reef solution 1ml per day. 175 14k mh 9 inches over 40breeder My lps such as my hammer and blastos look ok but i cant seem to keep very many polyps, ricordea or shrooms. Only a couple of species of zoas will live in my system. My crocea loves the system. I have an orange monti cap w/ purple polys that seems to do well ie white rim and great polyp extension. the same goes for alll caps in my system. I am just wondering if i should start adding like coral accel or something for greater growth. I use a euro reef cs 80 skimmer and boy does it pump the grunge. I am new at the sps thing... i got a few small frags when i switched to halides. I have had a Green pocillopora for a couple of weeks now and it is starting to get white tips....Is that a sign of growth like in acros? Thanks for reading and all the support i know i will get form all you guys.