I hear a lot of questions like: "How many fish can I put in?" "How many tangs?" How many for a CUC...how much should I feed? Can I have a school of fish? ---
The universal answer is: "A couple fewer than you may think."
Here's the reason. You set up your expensive tank in a period in your life when things are going pretty ok and when you are absolutely obsessed with your tank---a period that lasts quite a while. You watch every twitch of a fish's fins. You sit watching corals eat. You sit watching a worm crawl around the rock. You sit waiting for a zoa to open. A bubble doesn't pop without you noticing it.
Then life happens. Your job changes hours. A household member gets seriously ill. You're in a storm zone and have shingles all over your lawn. It's summer, and you've got a vacation planned---gone two weeks. It's winter, and the walk has to be shoveled 3x daily...
You're not watching that tank nearly as closely as before. You forget a few tests. You skip three water changes. Or more. You forget a filter change. You let the topoff reservoir run dry five days ago, and haven't noticed---yet. [me]
That's why 'fewer than you think'. You need wiggle-room in a tank. You need room for fish to grow, for a heater to go off or a thermostat to fail, for you to forget a filter once without catastrophe, for your salinity to spike once [me] without killing your tank, for a kalk overdose, for an emergency 5 day trip to ailing grandma's with no tanksitter available; for a 10 hour power out; for your AC to fail in a heatwave, or for you to have one of those temporary cooldowns in your interest and attention due to some pressing emergency or life-change.
This is why those of us who've been at this a long while beg and plead with newbies not to 'push' a tank's capacity. Have plenty of spare room in your tank---and plenty of 'room' in your tank chemistry. If your fish are using every smidge of oxygen it produces; if your live rock is barely keeping up with the biomass; if you've got cranky fish who start in on each other if not fed often; if you've got a skimmer that easily goes out of tune or a tank that's just plain carrying all the life it can---it takes just one event before the owner notices a fish belly-up (always the favorite) or all the corals sliming, or the water going greener by the hour (literally), or the fish all up gasping. If your nephew throws Cheerios into your tank---the already-stressed chemistry goes south fast. If you have an 8 hour power out, the maxed-out tank will crash and kill most everything. The tank with wiggle-room in its life-support will go 10 hours.
One small hint---even if you're a fish-only, install a small plain mushroom rock. As long as they're spread out and happy, your fish are going to be pretty ok. If you come into the room and they're shriveled or sliming, test fast and correct things. Fish don't complain: they just go belly-up or go into the rocks and the only advance signal you get is the absence of a particular fish who suffers adverse conditions earliest. Corals all complain early, while there's still plenty of time to do something---as good as running a constant, visible water test.
HTH, guys, with as good an explanation of reasons as I can give you.
The universal answer is: "A couple fewer than you may think."
Here's the reason. You set up your expensive tank in a period in your life when things are going pretty ok and when you are absolutely obsessed with your tank---a period that lasts quite a while. You watch every twitch of a fish's fins. You sit watching corals eat. You sit watching a worm crawl around the rock. You sit waiting for a zoa to open. A bubble doesn't pop without you noticing it.
Then life happens. Your job changes hours. A household member gets seriously ill. You're in a storm zone and have shingles all over your lawn. It's summer, and you've got a vacation planned---gone two weeks. It's winter, and the walk has to be shoveled 3x daily...
You're not watching that tank nearly as closely as before. You forget a few tests. You skip three water changes. Or more. You forget a filter change. You let the topoff reservoir run dry five days ago, and haven't noticed---yet. [me]
That's why 'fewer than you think'. You need wiggle-room in a tank. You need room for fish to grow, for a heater to go off or a thermostat to fail, for you to forget a filter once without catastrophe, for your salinity to spike once [me] without killing your tank, for a kalk overdose, for an emergency 5 day trip to ailing grandma's with no tanksitter available; for a 10 hour power out; for your AC to fail in a heatwave, or for you to have one of those temporary cooldowns in your interest and attention due to some pressing emergency or life-change.
This is why those of us who've been at this a long while beg and plead with newbies not to 'push' a tank's capacity. Have plenty of spare room in your tank---and plenty of 'room' in your tank chemistry. If your fish are using every smidge of oxygen it produces; if your live rock is barely keeping up with the biomass; if you've got cranky fish who start in on each other if not fed often; if you've got a skimmer that easily goes out of tune or a tank that's just plain carrying all the life it can---it takes just one event before the owner notices a fish belly-up (always the favorite) or all the corals sliming, or the water going greener by the hour (literally), or the fish all up gasping. If your nephew throws Cheerios into your tank---the already-stressed chemistry goes south fast. If you have an 8 hour power out, the maxed-out tank will crash and kill most everything. The tank with wiggle-room in its life-support will go 10 hours.
One small hint---even if you're a fish-only, install a small plain mushroom rock. As long as they're spread out and happy, your fish are going to be pretty ok. If you come into the room and they're shriveled or sliming, test fast and correct things. Fish don't complain: they just go belly-up or go into the rocks and the only advance signal you get is the absence of a particular fish who suffers adverse conditions earliest. Corals all complain early, while there's still plenty of time to do something---as good as running a constant, visible water test.
HTH, guys, with as good an explanation of reasons as I can give you.
