A few questions

Ok Iv been gathering up some questions and hopefully I can get a few answers.. sry for it being so long but half of it is because i spaced it to make it look cleaner

Ok!
Water changes...

Iv read alot on it already but its still a little confusing and I know its probably really easy but..

I Get water in a bucket a day before and ad salt.
How much salt?

And what does reverse osmoses do?

Then I air-ate it.

I have a fish tank that has like a bubble that I put underneath the gravel could i use that?

How do i filter my sand or do i even do that because I read somewhere to filter it?

!!!If theres any other important things thats helpful to know please ad!!!


Ok I know this isnt the right spot but its on my list of questions

Theres like this green algae thats growing in the back and on the sides not the front, So i tried to wipe it off with this sponge I have thats on a stick and that didnt work so I started scrubbing and the stuff still wont come off...

Is there anything I can do to get it off?

A couple more
Where do people that sell the live rock get it from.. going all the way back to the ocean, Do they just grab them out and sell them? they have to ad some sort of chemical or purifying...somthing? Cant you get BAD bacteria from that?

This one kinda has to deal with the first one
With a sump is that like the 20% water change or is that just a better filter?
Whats the difference?

I bought some live rock and I notice something new like every time I look at it but theres something living inside a crevice and I cant tell what it is but it looks almost like a worm but it opens up like a mouth at the end and like these branches come out and then retract and then come back out like its catching stuff and eating then goin back into place.. I took some pics but its hard to see..

 

get yourself a 5 gallon bucket and pull water out of the tank, keep track of how much dump the water out. You will probably want to do a 10% or 20% water change.
as far as the salt goes usually their are directions on the side of the box or bag to tell you how much to add per gallon.(like 1/2 cup per gallon). Make sure you check the salinity with a hydrometer before putting it in the tank. some people wait and let the mixed water sit over night , some add it after it is mixed.
What kind of salt are you using? brand?

its water that has been filtered, the best to use would be ro/di water.

get yourself a magfloat or other type of magnet scrapper. It will help out allot.

a sump is to add more water volume to your system and is "usually" another tank(smaller) under the main tank, where you can put equipment and stuff. you can also have a refugium to grow macro alge like cheato to help keep your nitrates and phos down.You run lines down to the sump and return the water with a return pump.

probably a bristle worm as I can't tell from the pics.
If you can get a better pic it would be easier to id it.

what do you plan on keeping and what size is your tank?
How long has it been set up?

 

hey wow thanks for all the answers!! im using the instant ocean for my salt, im told its the best in the area. well its a 20 gallon tank its been set up for probably around a month and a half and I plan on keeping a community tank of pretty much whatever can fit in with a clown fish ^^.. But im not sure if its the bristle worm b/c this thing is round like probably the width of an index fingernail.. Thanks again for all the answers il try and get some more pics up but hes got himself lodged in a hole in my live rock and doesnt come out...