If I couldn't use Magnesol I probably wouldn't even make bio! Water washing is just not the way to go if you want quality bio. Let it settle overnight, then a 10 mic filter, then a 5 mic filter, then a final with a 1Mic absolute. You can use just 1% Magnesol IF you remove the soap FIRST. I do that by vacuum. If you pull a vacuum on your bio the soap will come out of suspension and fall to the bottom and can be drained off.