Update as of 08/02/2013:

Moved the fish tank over to my place last Sunday. Was a long job, but got them over and the little guys were definitely stressed from all the rocking in the car. Anyways, because it was just me and my GF, we had to take as much water as possible to be able to lift the tank over to the car. So we had to take 80% of the water out and bring it home. Once brought in, I filled it up with water (the little guys were in 3 different zip loc bags), waited it to settle and such, then dropped the little guys in. 2 days later, I took the clown loach to a local pet shop and was able to find him his new home. The pet shop saw a few pictures of my plecko and said that type of plecko usually doesn't get anymore than 4 inches so it should be fine. Anyway, so what I have now is a plecko, pink tetra and 2 new buddies - one mickey mouse platy and the other one a yellow platy. From Sunday until now (Friday), I just cleaned up the tank a bit and by that I mean get rid of some old food that was laying there and cut off some of the hornwort plant since it seems to be spreading its wings everywhere. I tested the water levels and to my amazement, the ammonia is somehow still at 0, nitrate at 0 and nitrite at 0. Can anyone tell me how this is? 4 different fish and how can all my readings be 0? Since they are all 0, should I wait to change the water or do about 20-30% water change?
I only have one filter running too. I'm also thinking about giving the pink tetra away and getting a different fish.