RO/DI units vs TAP water.

What works for some people doesnt always work for others. My tds before RODI averages 425 then 0 coming out. I dont even consider using regular tap. If I had good water I would feel blessed and use it in a heart beat. I think OP is one of the lucky people out there that can get away with not having to use RODI water. Maybe he just has a talent, luck or is just that good at this that he doesnt experience or have the problems that some of us have. evidently he is doing alot of things right and if he can get away with using tap go for it.

 

Exactly.

I started my 35g on tap water. Biggest mistake I ever made with reefs. I started buying RO water from the store as it was better than the tap water option.

When I started my 90g up, I already had the RODI unit. I actually bought it when my 35g was a year or so old.

Now with the 200g, of course I use RO only.

Some folks can get away with tap, but IMHO, youa re really risking a lot by using it.

 

what happened was that my brother filled the tank with tap, without me knowing... but since i just got my RO unit im going to do water changes. 50 gallons.. one day.. then another 50. and then another 50. that should do it. right? cycle hasnt started or anything. im in the process of setting things up.

 

Three 50 gallon water changes will still leave stuff in the tank. Lets do the math

With a tds of 100 you are removing 25% during a water change. That leaves a tds reading of 75.
Do a second change and you are removinb 25% of 75 which comes out to 56.25.
Do a third change and you remove 25% of 56.25 which comes to 42.18
Do a fourth change and you remove 25% of 42.18 which comes to 31.6

As you see it is hard to get rid of all the left over junk as each change drops the levels less and less but ou are getting closer to zero so i guess it probably works out fine.

 

yea. maybe i can wait and just do a 50%. then keep with 25% or wait and do a 100%.

 

what?

 

You will never eliminate all the effects of the tap water no matter how many water changes you do. Many contaminants get into the rocks and sand and do not come out. Its not worth the risk if you plan to have a successful reef long term.

 

Once again this is not always true there is a small percentage of which it can work. Have been reefing for ten years with tap water, thats longs term and i am just as successful as any one else

 

Its only a matter of time. Not if, but when. Tap water is inconsistent and will bite you every time, guaranteed.

Try RO/DI and you'll never turn back. I am a treatment plant supervisor by profession, 35 years, and I won't use it. Too many variables outside your control. Its foolish to think otherwise.