Sounds like the pen thing will work fine. Well you are smarter than me because someone actually showed me how those pots and bases work and I still blew it....think I got em at Walmart. Oh that meter thing made me crazy! I could SEE the soil was wet but nooooo....You will find once you settle your drainage problems that your plants will be much more forgiving if you overwater a little....not a lot...a little. If you have something you can stick up into the holes to help areate that will help drainage too. Careful of the little roots tho.