Which direction for your tank---and how to be flexible...


Staff member
RC Mod
"Just starting out" is a time of high excitement and sometimes a time of choices you don't know you're making, until you're quite a way up a creek with a lot of branches.

Consider this: get as large a tank as is reasonable and practical. In the salt water hobby, particularly if you aim for fish, long and big is better. If you want to go to corals, lighting is a huge consideration, and lighting is expensive, so long and big may need to be 'zoned,' ie, the bright light at one spot and the rest not. Or just a smaller tank. Also consider how you're going to service this tank---because they do require access into the tank, and into the sump, if you have one.

Another piece of advice: start with basic, hardier fish until you've made your beginner mistakes---and most of us do make them. Big ones. Don't spring for spendy fish until you've done research on them, including Adult Size. Most fish (other than gobies and blennies) are sold as minnows, and some head for 'whale' real fast. Seriously. Little 'Dory''s adult size is a foot long. And some fish that aren't that big have 'swimming requirements' to thrive---sort of like housing a greyhound in your bathroom. Tangs fall into that category in general. A few are far more sedentary, like the kole and orange-shoulder, but many need quite a bit of room.
A caution on rabbitfish: they do get 10" long, 8" easy, and they are venomous. They also are freakout fish, and in too small a tank may start getting freaky and doing in their tankmates. I recommend leather gloves UNDER your heavyduty 'handling rock' rubber gloves if you have to move a lot of rock with one of these guys gone missing. They plaster themselves to the underside of rocks when panicked. Not good news if you grab them.
As a general rule, for tanks under 50 gallons, blennies, gobies, royal gramma, clowns are all good choices.
Angels: some grow big. The dwarfs that stay small MAY eat corals---some individuals do, some don't ever, or just pick on a few species. Not good for a tank destined for corals.

For a future reef: lighting is a big issue. Softie corals (leathers, mushrooms, etc) don't take as much. Stony large polyp (lps) is moderate, and the branching colored sticks (small-polyp, or sps) takes strong light AND superclear water, so you need very good light AND a killer skimmer for sps.

The big divide is whether or not you will do corals, and if so, what type. They're not hard (except sps) at all, and grow fairly fast; but certain fish WILL eat them, and you need to know that before you get fish. Blennies and gobies and clowns are safe: note: don't put them with giant mushrooms---mushrooms will trap and smother them. Angels are a 'no' to 'iffy'. Tangs are generally ok with them.

In general, ASK before you commit to a fish choice. Ask here in this forum for people with expertise. 'Reef safe' means it won't eat corals. For me, a 'reef safe' ghost eel did in 300.00 worth of fish before I could get him out. That was MY beginner mistake. He truly didn't eat corals. And being a night hunter, you wouldn't see him do it. But he did.

Nothing hard and fast here, just personal experience. There's nothing right or better about a particular type of tank, but it's a pain when your favorite fish turns out to be a no-go with the coral you want. And the time to think about that is during planning and before you've spent your money.



Staff member
RC Mod
Let me re-emphasize: nobody in this hobby is EXPECTED to be an expert starting out. Ask. Asking is good. I'm perfectly happy to explain the reasons behind what I say and try to make it clear. There are a few things you're bound to learn in this hobby: plumbing: after doing my tanks, I felt no qualms about completely replumbing the upstairs bathroom, or plumbing and installing a 5000 gallon koi pond in the back yard. Electricity: yep, you learn a deal of that, too---especially the part where it and water are a bad idea; GFI plugs are your friend. You learn a lot of biology. And you learn a LOT about saltwater chemistry, alkalinity, and what that lovely romantic sea foam REALLY is. All of us more experienced reefers who hang out in here are here because we actually enjoy helping people get started, so ask any of us with a lot of replies under our avatar and you probably have landed on someone for whom this is not their first rodeo. Happy to help.


I'm really very likeable
so ask any of us with a lot of replies under our avatar and you probably have landed on someone for whom this is not their first rodeo. Happy to help.

Crikey; comparing the size of your post tally to mine, I feel pretty lame now.:sad2:

I have lots of posts & replies on other forums, do they count?

I also started keeping aquariums when the Commodore 64 computer was considered high tech, & that was before Al Gore had invented the internet.

LOL, just joking, I understand where you're coming from. :thumbsup: :beer:

I'll just run along now.

Sinn Sage

The only thing free in this hobby is advice. Ask for it before you end up spending more money than you should to fix or replace something.

Measure once, measure twice, and measure three times........9pm on a Saturday night is not the time to find out that your new $300 skimmer will not fit inside your stand and sump.

For every dollar you spend on a fish or coral, expect to spend five dollars on support......food, dosing, water changes.

Don't expect to have a finished tankj in two weeks. Saltwater aquariums are like cheap wine, they come in cardboard boxes but yet take time to master.


Premium Member
My general rule of thumb is the sweet spot for ease of maintenance is tanks from 60 to 180 gal. 60 and below is where stability (temp,ph, etc) is difficult to maintain and above 180.. I may adjust that to 225 I'm running now, the sheer scale and size of the system become more difficult. on a 200 gal system, a 25% WC is 50 gallons. but on the other end, on a 25 gal tank, leave your AC of and you can wipe out the entire tank in one afternoon on a hot day. What could amount to a rounding error on addition of a carbonate hardness additive could also cause tremendous damage to your tank.

Lots of people run successful nano tanks for long periods of time, decades but they do require attention on a shorter interval. Larger tanks, you can often neglect for a month , assuming you maintain topoff water, and fish food and you wipe the glass for the first time in a month and the tank is banging.