Brand new setup - Skimmer questions...

how long has the water been in the tank with the rock?
if you do go and change all the water in one go, id sugest syphon some water from the tank into buckets and put the rock in there while you fill the tank back up.
the reason for not using tap water is that it contains more than just clorine the biggest thing in tap water to worrie about is phosphates that is a fertiliser to alge it will grow like mad and ruin the beauty of your tank.

is the filter you got a reverse osmosis filter? because that is what you need!

 

do you think a small 10 gal tank would need a nano skimmer?

 

i would say it would be too weak
there is some nano skimmers out there sutible for upto 16 gal but would be expensive.
you are better off gettin a slightly larger one because then you know it is more than capable for the volume of water it is skimming

 

Oh ok, thanks!

 

The rock has been in the water for two weeks. I've changed brands of de-chlorinator to one that is supposed to get along with skimmers better and after three 10g water changes the skimmer does not appear to be as bad however it still overflows the cup after about 15 seconds of run time.

The filter I have is not an RO. It is a non-replaceable canister (14" tall - 5" diameter) in-line filter that is made to remove chlorine and most other chems, colors and odors.

 

Update: The new conditioner (Prime) and the water changes seem to have done the trick. The skimmer is now operating as I had expected. Thanks for the help folks. I have plumbed the filter in below the bathroom sink (pic attached) and it looks like it will do the trick so no more conditioned water for me.

BTW - here is a pic of what was happening - the collection cup filled with water within 10 seconds and then just overflowed, non stop, back into the sump.