Does a Ro/Di filter remove all in tap water?

[SKYHIGGh]

Here’s my question then theory.

Does adding a RoDi system remove all in tap water?
Does 0 TDS mean O Alk?

So here’s my problem you alk has been 14-15 since at least since April!

Tested using Red Sea and salfrit

Here’s what I think tank has been up for about 3years now for the most part I have always used tap water in my ATO and my water change. Over the years my tank has had moments of it thriving in the softie and LPS types of corals but never sps always no growth no colors but not really deaths. Montis have always grown clowns have never died other fish have. I even have a clam that is growing in this high level of alk So on so on.

After hurricane Irma my tank crashed due to no power for about a week I loss everything it was depressing to say the least. Tank sat for about six months with just water running using Red Sea coral pro that starts with about 12Dkh. No water changes no corals I think tank just sat at the level.

I started tank back up in April bought corals changed out water with RC with all still around 12 out of the box but when mixed with my tap around 14.

I have stability down pact with a doser testing kits and ato and now picking up a RODi unit this weekend.

But am I wasting money. I read somewhere that tap water has all In it and when mixed with salt water those values add to the salt mixes content. Thus giving me this constant 14dkh I’m running?

Is this true?

My justification for buying the RODi unit is my tap water will be filtered at 0 tds 0 alk and if my salt mix is 8 it will stay 8 when I mix it so to speak.

I don’t want to buy a RODi if it does not change or remove the alk from the tap water as it is the sole purpose I want it for so I can start to reduce my alk levels with a new salt mix and water changes over a period of time. Want to get down to the 9 range. I figure new salt mixes at 8 add my doser to maintain and should be consistent.

 

[chipmunkofdoom2]

Your elevated alkalinity is likely coming from the tap water. Carbonate, calcium and magnesium are all common in tap water. There are other benefits of filtering your water as well. You don't have to worry about common contaminants like copper, or nutrients present in tap water (like nitrate and phosphate) affecting your reef.

 

[SKYHIGGh]

Your elevated alkalinity is likely coming from the tap water. Carbonate, calcium and magnesium are all common in tap water. There are other benefits of filtering your water as well. You don't have to worry about common contaminants like copper, or nutrients present in tap water (like nitrate and phosphate) affecting your reef.

I do have very high levels of the other two as well 1500-1600 mag and 440-480 calcium for months even with 5 Montis growing a clam growing nothing is ever depleted so to speak. I’ve gone a month before to see if the big three drop and they don’t it’s almost like my ato is dosing it lol

I do understand it will filter out everything else and that’s a great thing

But the core of the question is tap water with a 6dkh going in will it come out of RODi at a level of 0dkh?

 

[chipmunkofdoom2]

But the core of the question is tap water with a 6dkh going in will it come out of RODi at a level of 0dkh?

Yes. It is not possible for water to come out of an RO/DI unit at 0 ppm TDS and still have 106 ppm of calcium carbonate equivalents in it.