How to Do a Water Change

Why Water Changes Are Essential

In an aquarium, waste products (mainly nitrate) have nowhere to go. The only way to remove them is by physically replacing old water with new treated water.

How Much to Change

Situation	Amount	Frequency
Normal, lightly stocked	25%	Weekly
Heavily stocked	40-50%	Weekly
Emergency (ammonia spike)	50%	Daily

Golden rule: Never change more than 50% at once unless it's an emergency.

The Process

1. Unplug the heater — critical to prevent cracking.
2. Start the siphon with a gravel vacuum into a bucket.
3. Clean the substrate — push the vacuum in, let it lift debris. Clean one-third each week.
4. Prepare replacement water — add dechlorinator, match temperature (±1°C).
5. Pour slowly onto a plate to avoid disturbing substrate.
6. Plug heater back in.

Dechlorinating Your Water

Tap water contains chlorine or chloramine that kills beneficial bacteria and damages fish gills. Always treat replacement water.

• Seachem Prime: The gold standard. ₹300-500 for 100 ml.
• API Tap Water Conditioner: Budget option. ₹150-300.

Pro Tip: Never pour water directly onto substrate — it creates holes and disturbs plants. Use a plate or the tank lid to diffuse the flow.