Why 50% Weekly?
EI dosing deliberately overdoses nutrients. Without weekly reset, nitrate and phosphate climb to algae-promoting levels.
50% change reduces accumulated ferts to manageable levels without shocking plants.
Timing
Schedule water change the day before you dose fresh fertilizer rounds. This resets everything in sync.
Time of day: afternoon or evening so lights-on reset is clean.
Temperature and Parameters
Match incoming water to tank temperature within 1°C. Use warm tap water + RO mix or pre-heat change water.
Remineralized RO should match tank GH, KH, and TDS. Sudden swings stress plants and shrimp.
Dechlorination
Use a strong dechlorinator that neutralizes chloramine, not just chlorine. Dose for full tank volume for safety margin.
For 50% changes, pre-dose dechlorinator in change water container, mix thoroughly, then add.