brown coating on gravel

[arcade_maniac]

Hello, I have been involved with plumbing peoples tanks for about 5 years.but never learned how to care for. I purchased a 200 gal. established tank1 week ago. the tear down and rebuild went off perfect, only lost one small plant.this sat past. 1 week running. I did small stom affect and a vacuum. the replaced filters and 30 gal water. at lunch sat. did all my water tests.all were right there,calcium needed just a boost. but fine after that. sun morning everything fine.feed them 10am . all day into evening 11pm looked great. came home after work 5pm and sand was covered with rust covering.
what is this and what is off. snails and hermits arrive tues am. this tank was neglected and in tough shape. help is appreciated!!! or I will call anyone just leave #or mine 207-229-4486 Don

 

[reefkprz]

Its a diatom bloom, not really much to worry about you just totally unsettled the tank during the move and caused a mini cycle. no biggie. but just to be sure, why dont you tell us your actual parameters.
and what your useing for a water supply because if the previous owner was using reverse osmosis water and your using tap water you may have silicates in your tap water causeing the diatom bloom, just a thought.

 

[arcade_maniac]

possible answer I was using tap and letting it sit for a day. heating it on floor from radiant heat. ro filter to arrive in 2 days. to mix with ionic. this was the second big water change in 2 weeks. his bottom water 3inches smelled like bad low tide.have to find test tally done on sat.

 

[reefkprz]

If your parameters are good, I would just wait for the RO unit to arrive before doing any more water changes, unless You absolutly have to, tap water is kind of a gamble. I use it but I know all the chemicle contents of mine and how to deal with them. I used to use well water wich was great with the well I had because the water just happened to contain mostly stuff desirable in tank water. RO water is definatly safer than playing tap roulette though.