The one product every freshwater tank needs is a water conditioner, to make tap water safe. Beyond that, only use treatments when there's a clear reason, follow the dose on the label, and never mix medicines. Most tank problems are fixed with water changes and less food, not more bottles.
The essentials
1. Water conditioner (dechlorinator)
Municipal tap water is treated to make it safe for people to drink. Those disinfectants are harmful to fish and to the good bacteria in your filter. A conditioner neutralises them in seconds. Use it every time new tap water goes into the tank, dosed for the amount of new water, not the whole tank. Choose one that handles both chlorine and chloramine.
2. Bacteria starter
Live bacteria products help a new tank cycle faster and help a tank recover after a move, a filter problem or a medicine course. They're a help, not a shortcut: add fish slowly anyway. (More on this in water testing and the nitrogen cycle.)
3. Plant fertiliser (planted tanks only)
Live plants need feeding to grow well and to out-compete algae. Dose lightly and regularly. Overdosing feeds algae instead.
Use with care
- pH up and pH down. Chasing a perfect pH with chemicals causes sudden swings, which harm fish more than a slightly "wrong" but steady pH. Fix the cause instead.
- Algae killers. They treat the symptom, not the cause (too much light, too much food, not enough water changes). Killing a lot of algae at once can also lower oxygen overnight.
- Medicines. Work out what's wrong first. White spot, fin rot and fungus need different treatments. Take carbon out of the filter while medicating, because it absorbs the medicine. Copper-based medicines can kill shrimp and snails.
- Salt. Useful for some treatments, harmful to many plants and some fish. Only use it with a clear reason.
Never
- Soap, bleach or household cleaners on anything that goes into the tank. Keep a bucket that's used for the fish only.
- Aerosol sprays (air freshener, insect spray, furniture polish) near the tank. Air pumps pull them straight into the water.
- Dosing "just in case". Every unnecessary chemical is one more thing that can go wrong.
- Mixing two medicines at the same time, unless the label says it's safe.
- Expired products. Store them out of the sun and check dates.
Food counts too
Overfeeding is the biggest cause of poor water we see. Feed only what your fish finish in about two minutes, once or twice a day. Uneaten food rots and turns into ammonia. A good quality food also means less waste for the same nutrition.
What we use
On every Fish Tank Boys maintenance visit, our own fish food and standard water treatments are included in the monthly fee. You don't need to buy or store anything. If your fish need a specific medicine, we tell you first and explain why. We're also preparing our own range of food and water treatments, the same products we use on our rounds, for tank keepers to buy.
No more guessing which bottle to buy
Monthly maintenance with our own food and water treatments included.