Dechlorinator directly in tank after water change?

add dechlor for the entire tank if you are adding the water straight to the tank. otherwise, it will get too diluted and may not dechlorinate the water you add fast enough. personally, I always add my dechlor to the water i am putting in the tank first. i add the amount i need to the bucket I am using and then add the water. that way, the dechlor is mixed through the best it can short of using something to mix it.
 
Thanks for all the feedback everyone. The tank we are setting up is a 29 gallon. We are going to do a fishless cycle with Dr. Tim's One and Only and ammonium chloride. I'm an experienced saltwater reefer and I have had really good experiences with their products for cycling and maintaining beneficial bacteria. Not sure about the fish, I know my son has a keen interest in some of the loaches. We've had discussions about stocking limits, etc. and I had him put a list together of fish that fit his tank, but I have yet to look over it thoroughly. I think this is going to be a great learning experience for him. Thanks again for the help.
 
Well welcome to the FW side of the hobby!

For a 29g I would highly suggest dwarf chain loaches (aka sids, Y. sidthimunki) which are one of my absolute favorites. Kuhlis would be another loach option. Most other species get are too large and/or active for that size tank...but there are still plenty of other options for a community tank.
 
If you use Prime at a mere 2 drops per gallon, there's no reason to skimp. Always dose for the size of the tank... not the amount of replacement water going in.
 
I've been dosing a drop per gallon for years! Ok somtimes there are a few drops extra (but not intentional). It is just a matter of how much you wanna stretch your dollar!

I try to match the water temp but it is usually slightly off. Never harmed a fish yet. It actually causes somes of them to breed! I drop my plecos tank(s) 10 degrees all the time (80% water change). Not only adults but with juvies and they are hardie.
 
I judge temperature by feel. Fish don't seem to mind if it's not exact, especially in partial water changes where temp differences are further mitigated. I don't think most common hobby fish are that delicate. In their "natural" environments fish certainly encounter localized temp fluctuations, after a rain storm, for example.
 
I have always added dechlorinator before adding to the aquarium. I might be paranoid. I use a 5 gallon bucket that I use for a 10g, 29g, and a 60g.
 
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