Kurt_Nelson
Aquarium Advice Addict
... I guess Im still trying to find exact causes so it doesnt happen again in the future. I totally get the bioload thing, but I havent had any issues with ammonia at all ...
I think it's safe to say that with your initial "welcome to the hobby" experience, it won't happen again - assuming you stock your new tank at reasonable stocking levels. I think you've learned too much to let it happen again!
Bioload isn't just an ammonia thing. That's the obvious sign, but there's also the aspect that you can't put any exact numbers to and that's overcrowding. Overcrowding a tank is going to stress fish out. They all need their little places to call home, relax, and chill. If they're constantly being harassed, constantly running for their lives, and can never establish a "routine", then stress is going to start causing health issues. If the stress level in the tank is so high, they might not be able to eat. If left to its own, a tank will "naturally" even out the bioload... which I think yours did. Three fish is still too many for a long-term situation in my book, but its sure better than eight, and I think with fewer inhabitants (especially the damsel), your tank will finally be able to have some peace.
I know you only had a hydrometer so you really don't know what the salinity was when that water change happened. Even so, whatever the salinity was, you added 1 gallon of freshwater to 9 gallons of saltwater. Math is math, and that is a huge shift in salinity in a matter of seconds, regardless of the initial salinity levels. I'm guessing the pH took a huge shift for a while also, until it balanced out again. Just saying that even though the salinity levels themselves weren't known *for sure*, the change in those levels were.
While it really stinks what happened to you and these fish, I really can't imagine you're going to make the same mistake again. I bet a year down the road, you're going to have one killer reef tank - especially if you go with one of those NeoNanos!