Anyone else have problems with nitrite?

[Jujubee]

Last night I decided not to do a wc on the 10 gal. I had already done wc on my other 4 tanks and was exhausted. I figured the nitrite was a lot lower than it had been and that if check it in the morning. I did a test and nitrite and ammonia are at a 0!
I could not be happier.
Bad news though. Nitrites rise to 5+ in the 20 gal. I've been doing a 90% wc on the tank the last few days. Nitrite will drop between .50-1 ppm I know I should do another water change but I don't. Today I'll do one in the am and pm and see what readings are tonight/tomorrow.
My frog tank is also close to cycling. Ammonia is usually at a 0-.25 nitrites at a .25 and nitrate at around 5-10.

My fry tank is a little harder to deal with since it is so small. But easier to do wc on. My fry are healthy and don't seem to mind the changes. They even play in the water when I'm putting it in just like their mom

Thank you guys for the much needed help. I'll keep updating.

And Janis I will surely need help with my plants when the cycle is complete in the 20 gal.
I will get root tabs for the plants In my 10 gal
Would that be enough or should I dose the macro and micro as well? I've read you need tests for that as well but not really sure what to be looking for.
My platys are still nibbling on the leaves so I will probably start feeding some cucumber so they stay away from my greens haha

 

[Jujubee]

This is one of the little guys. They are growing so much!

 

[J.Mcpeak]

Relief at last (almost)

Well done with the fry!

Hopefully this will be the worst experience you have, fingers crossed.

Edit- yes on the updates!

 

[Rivercats]

You can PM me all the info on the tanks. Lighting and types of plants your using and then we can decide which ferts will be best for you to do. Your getting close to all of the tanks begin cycled and your work load will be cut way back!