SAC Prac - Designing the Experiment

[auds]

Hey all,
 
So for my part of my Prac SAC, I have to "design an experiment to analyse the concentration of iron (II) in a sample of lawn food fertiliser by redox titration." We're using potassium permanganate and sulfuric acid, along with the fertilizer. Just wondering if the following method I wrote is legitimate..... thanks in advance !

1. Coarsely grind the fertiliser
2. Transfer sample, without loss, to a clean 250mL standard flask containing a small amount of de-ionised water
3. Swirl flask to dissolve fertilizer
4. Filter fertiliser solution to remove insoluble material
5. Make the remaining fertiliser solution up to 250mL, using sulfuric acid
6. Pipette 20mL aliquots of the fertilizer solution into a conical flask
7. Titrate against potassium permanganate, swirling as the permanganate is added
8. The end point is when there is a perceptible permanent colour change
9. Repeat steps 6-8 until 3 concordant titres are obtained