Why can't I get a dark stain color on Maple wood using water based wood stain over pre-stain conditioner?

Maple is one of the most difficult woods to achieve a dark, uniform stain color on because it is a dense, closed grain wood and often absorbs stain very unevenly. General Finishes Gel Stains or Water Based Stains usually will perform very well because they are more topical than traditional liquid oil stains, and contain more colorants. 

We do not recommend pre-sealing Maple with a conditioner because it closes up the grain of the wood even more, further preventing color adherence. In the future, just use our water-based stains or gel stains on their own. Do not use liquid oil-based stains on Maple because they will blotch.

Also, prep sand Maple with 120 grit, followed by 150 grit or 220 grit.