Common Mistakes Setting Up A New Tank

by | Dec 15, 2005 | 0 comments

Common Mistakes Setting Up A New Tank:

  • Mistake number one: Not installing a GFCI before setting up the tank and stand.

— Laura D

  • heavily stocking a tank within the first few weeks of the initial setup
  • not providing adequate water flow around, under, and through a rock structure (dead spots)
  • placing damsels in a tank (intended to be a “community” tank) to “cycle” the tank
  • listening to 10 different people’s opinions all at once (find one person who has a tank that you like and follow their advice until you get on your feet)
  • impatience
  • not using RO water

— melas

  • Using an external overflow.
  • Underestimating the flow required.
  • Stocking too fast.
  • Overfeeding.
  • Overestimating how many fish can fit in a given space.
  • Putting fish that get large in small tanks because a larger tank will be purchased “a few years down the road.”
  • Placing parts and equipment that need to be frequently maintained (skimmer cups, filter bags,pumps) in hard to reach places.
  • Not preventing salt creep/plumbing leaks.
  • Not using a GFCI.
  • Not mounting plugs/power strips above water level and/or use ‘drip loops’. I still see experienced reefkeepers do this from time to time.
  • Purchasing animals when one is unaware of what the care requirements are, how large the animal gets, what it may or may not eat, or even what it is. Research before buying!!!

— Matt_Wandell

  • Only top off with freshwater, not saltwater.

— rcsheng

  • Investigate the eating habits of your animals, before you bring them home.

— Illflyaway

  • read, read, read…..
  • put your hands on the products you want to buy… if you can….
  • get a account before you buy anything…
  • be humble… books don’t teach you everything…

— LA-Lawman

  • Not making enough of an effort to buy captive bred organisms, rather than wild caught.

— Entacmaea

  • A GFCI is a Ground Fault Circuit Interruptor, it is a type of electrical outlet that you see most commonly in kitchen and bathrooms- around water- that will automatically break the circuit if a surge is detected, to protect electrocutions due to water.
  • RO is Reverse Osmosis, a way to purify water. A way to get very clean water for your tank is to purchase a filter that uses RO and DI, or Deionization. An RO/DI filter usually comes in 4 -stages, a carbon filter, mechanical filter, RO membrane, and a final DI cartridge.
  • As for buying captive bred- most stores do not breed their own fish, but often sell fish that are tank-raised, and also could sell corals that are tank-raised by other aquaculture companies. Nowadays, many fish and I would estimate at least 75% of all corals can be purchased as propagated, tank-raised specimens. Live rock and sand are also available in farmed versions. In my opinion, it is grossly irresponsible of a hobbyist to purchase a wild-caught specimen if there is a tank-raised equivalent available- especially with the state of reefs today-even if it costs a little more. Moreover, we should think twice about choosing organisms for our tanks that are not aquacultured- it should be one of the guiding principles when starting a new tank.

— Entacmaea

  • Trying to start off with cheap equipment and later upgrade to better stuff is a big mistake. You end up spending a whole lot more money in the long run and likely underestimating how bad your equipment really is.
  • Ask an experienced hobbiest which products to stay away from, because there is trully a lot of snake oil out there.
  • Before you do anything else, make a budget on what you can spend and what it will cost to set up a tank. Virtually all newscomers grossly underestimate what it costs to have a reef tank.
  • For limited budgets, start with FOWLR and a really good protein skimmer, then when you are ready, make the jump to a good PC, VHO, T5, or best: metal halide light fixture.
  • Read all back issues of Advanced Aquarist & Reefkeeping Online Magazine. By then you may have enough knowledge and experience to attempt to keep corals.

— brandonberry

  • Not doing water changes during the cycle and allowing ammonia to climb so high it diminishes the critter diversity in the live rock.
  • Stocking too fast.
  • Using Tap water “just to start””.
  • Overstocking by not considering the adult size of the fish.
  • Not researching the needs of the livestock.
  • Trying to fix problems using bottled additives.
  • Trying to build a reef tank on a Guppy budget.

— Guy

  • Not calculating enough flow and having the “I’ll get a pump later” mentality. By the time you do get pump(s) to fix the flow issue your LR will have detritius built up on it, probalby nuisance algae, etc. Things like lighting can be added later as coral demands need it, but flow is something that is important from day 1.

— sfsuphysics

  • Not buying the proper equipment the first time.
  • Listening to the guy or gal at the LFS.


  • Buying the cheapest tank instead of the right tank.
  • Buying a fish or invert on impulse.
  • Thinking that my fish would be the exception in its dietary needs then having it eat my corals.

— Oceans Ferevh

  • Not sizing the sump large enough to account for water drainage from the display tank during power outages or pump failures.
  • I don’t know how many times I’ve heard people say “wow, the display tank’s water level is that low whenthe pump is off!”

— SciGuy2

  • Listening to opinions from too many sources.
  • Trying to cut corners on equipment.
  • Having too much Bio-filtration.
  • Having too little mechanical filtration.
  • Not having adiquate UV Sterilization.
  • Misadjustment of my Protein Skimmer’s gate valve.
  • Not keeping a balanced livestock diversity. IMO balancing the ecosystem is key to having a healthy reef.

— HisKid

  • Not keeping freshwater fish first. I have had several people see my tank and want one at home. A few have gone out and bought a set-up…sold the set-up because it is too much work. I tell everyone who has never kept fish to do freshwater for 6months to a year so you get an idea of tank maintaince, ect ect. During that time READ, READ, READ!!!

— Rob Top