Welcome to TFK!!!
I would love to see some pictures of your tank!
Originally Posted by Carny77
1. In addition to the weekly water changes that I am currently doing, how often should I clean my filter and change the cartridge? I have seen posts suggesting leaving in the old filter for a few days and "seeding" the new filter with that. Thoughts/suggestions?
This is my opinion, and many people will say many different things.
Depending on your filter. Mine deteriorates if I don't switch it, because of that when I see it starting to break apart I switch the pad. Probably Once a month. Others on here only rinse theirs and switch our the carbon.
The biggest point is that you are messing with the bacteria. Honestly, there should be enough bacteria in your tank...in the substrate, plants and decoration that removing the filter media and replacing with a brand new one or just simply cleaning it will not do any harm. I would say wait as long as you can to clean it. If you have one of those filter pads that don't decompose then you should never really replace it. You can just rinse it in the old aquarium water when you do water changes.
Originally Posted by Carny77
2. It's time to start stocking. I'd like to add more tetras to give them a better number in which to school. I'd ideally like mostly smaller fish in the tank, staying away from bigger "centerpiece" fish. Suggestions as to what to add and how often I may do so, now that I believe my tank is cycled and stable?
Thanks in advance and sorry for the lengthy post...
2 Danios and 4 Neons?
I would suggest raising that Neon number to at least 8 to get the schooling and super happy. I have 11 of them in my 29 and they are beautiful schooling together.
You can probably add the 4-6 new neons at once without a problem as long as you monitor the water. I would def no add more than 6 neons at once just to be safe.
I would also in the end have at least 5 Danios. They like to be in schools and any schooling fish will do best in at least a group of 5. Byron has posted some articles on stress and health of schooling fish and how their life span is increased just by at least having 5 fish of a schooling species. Do you have live plants?
That will truly help with adding stock and especially with adding more numbers than you are supposed to.
It sounds like you are going slow and doing great! I wish I had taken it slow as you are and really sat to think about what I wanted to put in my tanks.
Before I suggest any new different types of fish for you to keep, we are all going to need to know some things. What is your gH and kH (Water Hardness)? pH LeveL?
This is a great thread with a HUGE list of fish that you could potentially keep in your tank: Nano Fish
If I were you I would consider a substrate fish. One school of the many species of Cory Catfish would go well in your tank. A Bristlenose Pleco
would do great if you had some driftwood and plants in there.