i am dumb please help me sw

[philhawk]

i have a 30 gallon sw tank. i bought it used and it has now been running for about 4 months if you can call it that. i can not keep anything alive for more than a week! (very upsetting) damsels or false clowns.

i have an
ac50 w/carbon
visi-jet protein skimmer (rarely produces any foam no matter how much i tinker with it)
1.5-2" argonite sand
1 piece 2lb aquacultured live rock
a few decorations

specific gravity 1.022(marineland instant ocean hydrometer)
nitrate 15ppm
nitrite 0ppm
ammonia 0 ppm
ph 8.0

2 blue legged hermit crabs (been doing fine since the begining)
1 horseshoe crab (had for about 2 months, doing fine with supplemental mysis shimp feeding)

i get a damsel or false clown and he gets aclimated in, is fine swimmin around for a week or so then dies. i check the parameters and every thing seems fine on the charts. i do a 20% water change and try again.

i dont understand why these inverts would be doing fine with fish doing so poorly

i am planing on live rock this summer and have a refugium built that needs to be hooked up (15 gal refugium diy w/diy overflow)

whats going on!

 

[sprayin70]

You will need alot of live rock because ALL BIOLOGICAL FILTRATION IN A SALT TANKS COMES FROM LIVE ROCK AND LIVE SAND. You only have a bit of live rock. I would say that your tank never cycled. I would add 30 plus lbs of live rock and then put a peice of raw shrimp from kroger in it until your ammonia spikes then take it out. This will start your cycle. Then just leave it alone no wc's until it cycled My tank took almost a month with 150lbs of live rock and 80 lbs of live sand in a 75. That is why your fish are dying. Also your skimmer needs a constant water level and "waste to skim" It will start to skim when bio waste in present. Also make sure you are skimming during youe cycle. If you do those things your tank should be ok. No more fish until it is cycled or they will just die too.