Ever notice that there are lots of articles and posts out there with titles like “The Top 10 Mistakes Novice Marine Aquarists Make”? Considering that newcomers are generally much more susceptible to making major errors than their experienced counterparts are, this stands to reason. However, just because the slip-up spotlight is usually focused on newbies doesn’t mean experienced hobbyists never make mistakes. In fact, they still make their share of blunders, most of which stem from complacency or overconfidence. So, turnabout being fair play—and to give hobby newcomers a break for a change—let’s look at what I would consider the 5 most common mistakes experienced marine aquarists make:

1. Failing to test Experienced hobbyists may like to believe they can ascertain the nitrate level in their tank by simply sniffing the water (“Mmm, smells like 20 ppm to me. Time for a water change!”), but the fact of the matter is, routine testing of water parameters is just as important for advanced hobbyists as it is for newbies. True, they probably have a pretty solid maintenance regimen in place, so water-quality problems aren’t likely to develop suddenly MORE