New maintenance advice

Ok, so you guys helped me out when my Cory's and tetras were dying in my brand new uncycled tank....(yes I know...I'm a fish dummy) with ur knowledge you helped me save my last 2 who were almost dead. Now happily zipping about! Thanks again. I did not cycle my tank at all before adding them, bought all the same day set it up sqeaky clean...not good. After some water reconfiguring, they have tolerated the new tank well, what's left of my fish anyway. Cory's, Platys and Mystery Snails. Everyone is happy. But my next question is this...

It's been a few days, water looks good, levels are good. But since I'm basically doing a "fish in cycle" Give me some instruction please. What percentage and how often do I need to be changing some of this water? Someone said just a little every few days? What to look for in level changes etc? Any advice would be helpful it's a 20 gallon filtered tank again uncycled at beginning now fish in cycle

 

To know for certain you should invest in the API Master Test kit. You'll be able to know your exact parameters. You'll know your cycle is complete when you have 0 ammonia, 0 nitrite, and a presence of nitrates. Do not add any fish until the cycle finishes. If you see readings above 0 for ammonia and nitrite, you're going to want to water change. Corys are very sensitive to bad water.

 

I agree that you need a test kit to guide your water changes. As you're cycling, add the results for ammonia and nitrites. Don't do water changes based on a set schedule, do water changes based on your test readings. If you keep combined ammonia and nitrites at 1 ppm or below, your fish will be fine but there will still be enough ammonia to keep the cycle going.

Test strips are notorious for being unreliable. The API Master Test Kit is by far the largest selling kit, probably because it's accurate and not that expensive in comparison to other good kits. You should be able to get the API Master kit for around $25 on Amazon. It will provide for lots of tests, and will serve you for a long time since you won't need to test that often once your tank is cycled.

 

What model filter do you have on your 20 gallon ?

If it is a cartridge based filter, I would suggest to add a block of foam sponge cut to fit the inside of the reservoir. This type of media will colonize a lot more beneficial bacteria compared to a cartridge and will catch a ton more muck also

 

Did you use Tetra Safe Start? I know they say to not do any water changes for two weeks after using it.