I have a plant only tank. (No fish, shrimp, snails, except pest bladder wort) reside in it. When doing a water change can I just pump tap back into the tank and forget about the conditioner?

That is what I do in my tanks with no livestock. Almost no water changes, just top off with tap water, no dechlor. When I do a BIG water change (like when I moved the tanks) I did use dechlor. But just that once.

Even with livestock I can top off with no dechlor, as long as the amount of the top off is less than 10% of the volume of the tank. My tap water tests 1 ppm chlorine and ammonia from chloramine.

I do a 50% water change a week to reset my ferts. I just want to know if it is okay to put regular (untreated tap) water back into the tank.

I'm sure as long as your not replacing 50% of your water with tap you'd be fine. But I would just bcz plant typically don't like chlorine. But I say why not? If you buy a decent size bottle it's more concentrated and you can use like 3/4 of a cap for a 50% weekly water change on a 75. Of course I have a lot of fish but I still do this every sun 50% to reset the EI weekly cycle. I'm sure you could dial in your fert usage with tests and basicly never water change with zero livestock I'm no expert but I think this is truth. Any pics? I love plant only tanks

Hello Z...

Plants aren't negatively affected by toxins like ammonia, chlorine and chloramine. I put water straight from the tap into the pots I keep my houseplants in, so I'd say your aquarium plants would be fine with water straight from the tap.

B

It is my 40 gallon "garden". Link is in my signature.