Most water problems are solved by water changes and patience. A small number genuinely need a product. Knowing which is which saves money and fish.
Conditioner is the one you always need
San Diego tap water is treated with chloramine, not plain chlorine, and that distinction matters. Chlorine gasses off if you leave water standing; chloramine does not. Letting a bucket sit overnight — advice you will find all over the internet — does nothing here. Use a conditioner that explicitly states it neutralizes chloramine and the ammonia released when it breaks apart, and dose every drop of new water going into the tank.
Cycling: bacteria, not chemicals
A new tank needs a bacterial colony capable of processing ammonia, and that takes weeks, not days. Bottled bacteria can shorten it meaningfully and is worth using, but nothing skips it. If you are mid-cycle with fish already in the tank, an ammonia detoxifier buys you time between water changes — it is a bandage, not a cure, and the water changes are still the treatment.
Test before you dose
The most expensive mistake in this aisle is treating a symptom without knowing the cause. Cloudy water can be a bacterial bloom in a new tank, which resolves on its own, or it can be overfeeding, which will not. A liquid test kit for ammonia, nitrite, nitrate and pH tells you which. Bring us a sample and we will read it for free — it takes two minutes, and it is often the difference between doing something and doing nothing, which is frequently the right answer.
If you keep shrimp or snails
Check every label for copper before it goes anywhere near the tank. Invertebrates are far more sensitive to it than fish, and it appears in more treatments than people expect. If a product does not explicitly say invertebrate-safe, treat the fish in a separate tank.
See also fish medication, filters and our guides.
