Note: If the bath size is large than 5m³, it is generally recommended to apply the ratio of phosphoric acid (85%) : sulphuric acid (98%) =7:3 for two acids bath make-up; while the bath size is less than 5m³ and the polishing effect requirement is not very high then can apply the ratio of phosphoric acid (85%) : sulphuric acid (98%) =1:1 for two acids bath make-up.

The bath solution maintenance of LW-38 is relatively simple：

1) Replenish the phosphoric acid, sulphuric acid and LW-38 by proper bath make-up ratio when the bath solution level gets down (no need to add aluminum chips when replenishment). 

2) It is not necessary to analyze the bath solution frequently, but only necessary to analyze the phosphoric acid, sulphuric acid, water and aluminum ions content every few days or when problems occur, and adjust them to the parameter range.