Ideal TDS

[IceNein]

I have been waiting for years for someone to say “Avogadro.”

Must have been one of those darn millenials. They're always going on about their Avogadro toast.

 

[DanyL]

We (everyone back before 1990 or so) used dechlorinated tap water to make our saltwater with, we had no issues. Being told not to use water with a TDS of 18 is just an untruth!

For you peeps that live by ICP testing, I'd be curious to see the difference in salt water mixed with 0 tds rodi and tap water. I wholeheartedly agree that 0 tds rodi is the best thing to use to mix fresh saltwater, using rodi with a little higher tds is not going to do any harm.

This is a very generalized view which does not fit everyone’s situation or desires.

When a new reefer uses tap water and than asks for advice with his Algea problem, or why his corals constantly die, just to find out that in his particular area, even though the tap water has low TDS it is full of heavy metals, including copper.. and then he says “but look, it works for him” - that’s a problem.

Just recently a local had an emergency and couldn’t fill RODI water for his ATO when he had to abruptly leave the house for a week.
He used tap water instead, when he came back all of his parameters were thrown off, and he began to fight the algae bloom that it caused. Nothing died immediately, sure. But the algae end up smothering some corals to death.

The thing is, people need to be aware of why 0 TDS is the norm, and that yes, in some cases it is possible to use tap water, or just RO without the DI, but it all depends on the quality of the source water they use to begin with.

It’s just easier to follow and recommend a ground rule for success that fits all cases, and not only some.

Edit: oh dang. I completely missed the whole discussion that gone after this comment, and seem like there was a lot going on, I haven’t read everything yet to to assess wether what I’ve written here has been said or not just yet.

 

[IceNein]

I think everyone should agree that starting with 0 TDS is useful to establish a baseline, because 100 TDS could be sodium and chlorine, or it could be copper. One of them will have no effect at all on your tank, the other will kill every invert in it.

I mean, a lot of people who live in coastal areas like San Diego, well mostly the TDS in your water are things that you are going to put back into the water, but if you strip it out then you can know almost exactly what is going into your tank.

 

[Reeferbadness]

My TDS reads 0 ppm when coming out of my RODI but has some positive number when measured in my 50g drum - likely just dust or other contaminants that are fine. Most likely salt or something else in the bucket

 

[Lasse]

but what could potentially, stastically or historically been an issue getting pass a good RO filtration system?

Copper and zink from the pipe system of your house

Sincerely Lasse

 

[trevor.allen]

Nope, has to be zero, no exceptions.

so i have 2 clowns 1 bi color angelfish 2 cleaner shrimp and chocolate ship starfish
wondering what my tds should be i have NO CORAL just fish