What your aquarium's water clarity is trying to tell you

The Maskotis office tank has survived four moves and one HVAC failure. The credit goes to two of our engineers who treat it as a small, slow co-worker. We asked them how they read the water at a glance.

Cloudy white, especially in a new tank, is usually a bacterial bloom. Annoying, mostly harmless, often resolves itself within a week of patient water-changes. Don't overfeed.

Green tinge is algae having a good week. The fix is light, not a chemical. Reduce the photoperiod and inspect the placement of the tank. Direct sun is rarely your friend here.

Tea-coloured or yellow-tinted water is tannins from driftwood, and is usually fine for the fish, less fine for the photographs. If you don't want it, a charcoal filter clears it in days.

What should worry you: a sudden change. Whatever the colour is on Monday, you want it to be the same colour on Friday. Quick shifts, not the colour itself, are the signal worth chasing.