I just filled the new one yesterday and added a heater today. The old one, they've been in since Monday. I bought aquarium sand from Petsmart. Not sure of the brand.
Here's the sequence of events: since may they've been in the same tank. I had to move quickly so I syphoned half the water, moved them (I know, shouldn't move a tank with water in it), then bought a new tank. Took some water from the original tank, same plants and set up a new tank. Readings all fine. Set up the new tank Monday and acclimated and transferred the fish that night. Then realized the new tank leaked, otherwise I would leave them in it. Cleaned their original tank (no chemicals or detergant, but I had a huge snail problem that I needed to fix) and planted it yesterday. Filled it today
So, they've been in the tank they're in since Monday and their new (original) tank was ready today.
Of course, none of this was ideal but I had to move so I did the best I thought I could. Now I just want to get them back into their home. And I'd like to get my bathtub back.
