When buying stocks in a margin account with your earnings for the day, do those stocks reduce your buying power until sold?

I have just opened a margin account. I like to day trade and put the profits back into long stocks. If I buy stocks with those profits, will my available buying power be reduced until they are sold since they will technically be bought on margin too in this account? Would the way to remedy this be to move cash into a regular cash account at the end of the day and buy my stocks there?

Muchas Gracias