Water Change Log

Tank Name / Location:

Tank Size (gal):

Water Type (FW / SW / Brackish):

Date Started:

Filter / Turnover (gph):

Heater (watts):

Record every water change so you can see your routine at a glance and tie it to your test results.

Water change basics

Most tanks do well with a 10-25% change weekly; heavily stocked tanks need more.
Always dechlorinate new water, dose conditioner to the FULL tank volume per the label.
Match temperature closely to avoid shocking fish.
Vacuum the substrate during changes to remove waste before it becomes nitrate.
For saltwater, mix and match salinity and temperature before adding.

Date	% Changed	Gallons	Conditioner Dose	Temp Matched?	Notes

Notes

Conditioner brand, substrate vacuuming, fish reaction, salinity (if saltwater).

Dose dechlorinator for your full tank volume, not just the water removed, unless the product label says otherwise. Never add untreated tap water to a stocked tank.