Water Conditioners and Tank Starters for Planted Tanks
Tap water usually contains chlorine or chloramine that harms fish, shrimp and the bacteria in your filter. This page compares conditioners, bacterial starters and mineral supplements using the dose rates and safety statements their makers publish.
What matters most
Chlorine or chloramine
Check your water utility's report to see which disinfectant it uses. Some conditioners need a higher dose for chloramine, so read the label for your water type.
Ammonia binding during cycling
Some conditioners also detoxify ammonia and nitrite, which helps while a new tank cycles. Others only dechlorinate, which is fine for an established tank.
Shrimp and invertebrates
Only some makers state invertebrate safety outright. If you keep shrimp, favor a product whose maker says so, and dose carefully in small tanks.
Conditioner, starter or mineral supplement
A conditioner treats tap water, a bacterial starter seeds the filter, and a mineral supplement adds hardness back to RO or very soft water. Many planted tanks need a conditioner; the others depend on your setup.
Check before you buy
- Does my tap water use chlorine or chloramine?
- Is my tank new and still cycling?
- Do I keep shrimp, snails or other invertebrates?
- How much water do I change each week?
- Am I using RO, DI or very soft tap water?
Skip a dechlorinator only if you fill your tank exclusively with untreated RO, DI or well water that has no chlorine or chloramine.
Ready to choose?
We have checked 10 water conditioners options for identity, specifications, and fit. Compare them, with what each needs and who should skip it, here: