Hi. Use to have a 55gal. saltwater tank... but recently purchased a 120gal tank for my porcupine puffer to live. After circulating it... I slowly started adding the old tank water to the new water, testing it daily to make sure the salinity was good, ph, nitrates, nitrites, blah blah. all is perfect. Finally the final step... moving my fish...
Umi the puffer, Naruto the clown, and Cloud the blue/green chromis.
After 2 weeks they all seemed to be adoring their new surroundings.
Here are pictures of my fishy friends.

Here's UMI my porcupine Puffer. (He's now 3 months old)

Here are Naruto and Cloud the Clown and Chromis. Both are about 8 years old.
They all seemed to leave well enough alone...
Sadly
Until today.
Cloud accidentally got killed by Umi. And I feel terrible. Umi didn't attack him... he never attacked them, even in the smaller tank. He's a fairly level tempered fish. But what happened was...
I always feed Umi his krill, then I feed the others their flakes... today for some reason... Cloud was interested in Umi's Krill. He's never cared before. Even in the smaller tank he never paid attention. But today he was curious and wanted to get up close to it.
When Umi was lunging for the Krill, Cloud swam in front of it at just that moment and got caught in the face by Umi.
Umi let go right away and swam away. Cloud swam in the other direction.
I left the other tank running as a sick tank and immediately took cloud out and put him into the sick tank. but I knew it was too late.
At first he was looking normal... but I could see he had teeth marks near his mouth where he got bit.
Within seconds his skin started getting purple/red spots all over as the posion started working its way through. It went so fast there was nothing I could do.
Cloud died 2 minutes after being bitten. I didn't even have time to humanely Euthanize him. I feel so bad. I had him for so long. And even worse, a few months ago, his buddy died of old age.
*Sigh* I feel so bad. I was thinking of keeping them apart and just giving the whole 120g tank to Umi and leaving the other 2 in the 55... but I thought... Umi is still small... It would just be the three of them... there's plenty of room, plenty of hiding places... they're all fed well enough... and like I said... they got along in the samller tank so now they have even more room to avoid eachother...
And for a long time they did get along in the bigger tank... it was a total accident... Umi was trying to go for the krill, not Cloud. Cloud just swam between them before Umi could stop. Its partially my fault. I should have shooed him away before dropping the Krill in.
I feel bad for Naruto too. Now he's without both his chromis buddies. :(
But Umi and Naruto are both ok. I think Umi felt kind of bad in a weird way. After it happened... he actually swam away as if he knew he did something bad... and it took him almost an hour to coax him to eat some krill. It was like he was scared to take it. but he finally ate, and settled back down. Naruto ate ok too, so I think they'll get over it sooner than I will.
Well... that's the update for now.
The soap opera will continue next week.