After peeling off the form for my footer, I noticed the concrete is not smooth in some places. Some chunks have fallen out and other spots looks really chunky/rugged:
(https://i147.photobucket.com/albums/r288/quitesweet/Building/Playhouse/Foundation-Pier7.jpg)
(https://i147.photobucket.com/albums/r288/quitesweet/Building/Playhouse/Foundation-Pier8.jpg)
I presume this is a mistake in not having enough water in the mix before pouring.
Is there a way to seal-in those spots, ie concrete caulk, filler or something similar?
It's just because you didn't tap the form with a hammer or vibrate the form to get the concrete to fill everything tightly. I wouldn't worry about it with the steel you put in there inless ther aer totally massive voids.
They will fill fill in with gravel etc. and shouldn't give you any problem. I saw a coke-head foreman on a job not use a stinger-vibrater on the forms on an ICF wall. He had massive voids and still passed city inspection - He patched the worst ones with concrete.
If you had just poured it in the hole, the same thing could have happened but you wouldn't see it to worry about it, and everything would still work just fine. :)
Adding too much water causes the concrete to be weaker.