why water changes?

[Marvin]

Basic Question.

Why water changes? Just wanted to know basic reason why?

Sorry if this sounds dumb.

Thx

[ben72227]

mainly to get fresh salt water in the tank and to lower nitrates, ammonia, etc.

[TKOS]

While it may seem that adding top off water will suffice since the good bacteria take care of things like ammonia and nitrites, eventually things like phosphates and nitrates can build up to toxic levels, along with other things. Taking water out and replacing it with fresh water will help to eliminate this. That is the simple reason why.

[Marvin]

ok..

Now, does this water change and/or topping off of water help w/ the brown stuff (sorry about the description) that accumulates on the glass, rocks, and crushed coral sand base?

Can anyone tell me what this brown stuff is?

Thanks again, and you guys are quick with answers.

[Gealcath]

The Brown stuff is diatom algae, they feed off Nitrates, Phosphates, and free traces of Silicon. Basically Nitrates and Phosphates are plant food, so in large amounts plants grow, which is algae.

[ben72227]

if you want to get rid of the "brown stuff" then you should get some mexican turbo snails or margarita snails and you can have a "clean up" crew to get rid of algae, left over food, etc.

[Marvin]

One more question, I think.

My brother helped me set up my37g tank and also told me to use a magnetic brush cleaner for the glass to clean off the brown algae.

He also gave me a "tube like thing" to sift through the sand base (Crushed coral in my case) and suck up the brown stuff on the base.

However, Im not quite sure if that is the best thing. My understanding is that there is good bateria in the sand bed so i should leave the sand bed alone.

Are these two steps normal to keeping a tank clean?

[ben72227]

you will probably need the tube like thing for crushed coral, as CC just traps debris and, you're right, some bacteria grows in it, but it won't hurt to use the tube thing to sift the coral around and get the trapped particles moving around to get sucked up by the filter.

[Marvin]

ah, thanks for the info

you guys are great!