Here's the good news and the bad news. I think your pleco might not be a common pleco. (That's the good news.) But I am not an expert. He might be a Bristlenose. I have several Bristlenoses that looked like him before they developed their bristles.
Having an extra tank is never a problem. Great you are upgrading.
Here's the bad news. Your tanks isn't cycled, unless someone gave you old filter gunge. A tank needs about 6 weeks to cycle. Cycling means you have developed enough bacteria to start the nitrogen cycle in your tank.
The nitrogen cycle is when bacteria breaks down Ammonia and turns it to Nitrite and another bacteria breaks down Nitrite to Nitrate. Then you vacuum out the Nitrate when you change water. Your readings should be Ammonia 0, Nitrite 0 and Nitrate less than 20. Because I believe your tank isn't cycled, as your fish continue to go to the bathroom in the tank, the Ammonia will rise to toxic levels. This is deadly for the fish. When the bacteria start to grow and change the Ammonia, the Nitrite will spike to toxic levels, and then the bacteria will grow and turn it to Nitrate.
Another bad news: the strips don't work, in my opinion. I learned that the hard way, because I have strips. The liquid is a million times better/accurate.
https://www.fosterandsmithaquatics.com/ ... catid=4454
Because your tank is probably not cycled, you will need to do tests twice a day at least. If your Ammonia goes above .5, do a 20% water change. If you use Prime as your conditioner, you will get a false position with API test kit. It will read .5 hen it is 0. However, your Ammonia will probably be 1-8 as it cycles.
If someone else gives you advice, listen to them. Remember I am a beginner. If your tank isn't cycled. You may want to see if your local aquarium club or friend can give you some filter gunge. Or you may want to see if you can board your fish until your tank is cycled.
