20 TDS

[ReeferNick13]

Hi all, what is your opinion on using 20-25 TDS rodi water for mixing and top off? I KNOW 0 TDS IS BEST. Curious if anyone is using around 20 TDS and hasn't noticed any negative side effects. Right now I am running a FOWLR system with corals possibly coming later down the line. I have only used 0 TDS rodi in my past tanks, I am just curious if anyone has or is using around 20ish TDS water with success. Please let me know your experiences with this, thanks

 

[Jekyl]

Problem is you have no idea what you're introducing. With corals I wouldn't use it

 

[Rjukan]

Hi all, what is your opinion on using 20-25 TDS rodi water for mixing and top off? I KNOW 0 TDS IS BEST. Curious if anyone is using around 20 TDS and hasn't noticed any negative side effects. Right now I am running a FOWLR system with corals possibly coming later down the line. I have only used 0 TDS rodi in my past tanks, I am just curious if anyone has or is using around 20ish TDS water with success. Please let me know your experiences with this, thanks

Why is your rodi water so high in TDS? Is your source water in the hundreds?

 

[Randy Holmes-Farley Verified Community Expert]

Is that ro/di water, or something else?

 

[DanyL]

It sounds more like RO water than RODI.

The problem with using TDS above 0 is that you have no idea what is in there.
One reefer can have a lot of copper and zinc, and the other can have silver and gold (I wish lol).

Unless you regularly test your high TDS RODI water with ICP tests, you’re basically gambling with what you’re introducing into your tank, and at the cost of these ICPs, you’d easily be able to maintain a 0 TDS RODI system in the first place, and likely even cheaper.

 

[ReeferNick13]

My tap water is 300+ TDS. I do have a 4 stage RODI system that I use for my tanks so I have no problem making 0 TDS water. The reason why I am asking this question is because I just installed an under the sink RO system for drinking water that has an output of around 20 tds. I was contemplating using the water from that system being that the output is Much faster than me making it with the 4 stage... it would save me a lot of time. BUT I just came to the realization that it is just an RO filter, not RODI... and with the 20 tds it doesn't sound like it will be a good idea to use. For a second I thought wow I can save hours if I use this water for my fish tank haha but I will continue to use the 4 stage with the 0 tds output. Also was honestly curious if anyone (knowingly) used 20ish tds water for their tanks and how it has worked out for them. Thank you guys for the responses

 

[Randy Holmes-Farley Verified Community Expert]

My tap water is 300+ TDS. I do have a 4 stage RODI system that I use for my tanks so I have no problem making 0 TDS water. The reason why I am asking this question is because I just installed an under the sink RO system for drinking water that has an output of around 20 tds. I was contemplating using the water from that system being that the output is Much faster than me making it with the 4 stage... it would save me a lot of time. BUT I just came to the realization that it is just an RO filter, not RODI... and with the 20 tds it doesn't sound like it will be a good idea to use. For a second I thought wow I can save hours if I use this water for my fish tank haha but I will continue to use the 4 stage with the 0 tds output. Also was honestly curious if anyone (knowingly) used 20ish tds water for their tanks and how it has worked out for them. Thank you guys for the responses

Whether that 20 ppm is ok depends on what is in your source water. If your water company adds silicate, the 20 ppm may have quite a large amount of it since it passes an ro membrane fairly well as silicic acid.

 

[DanyL]

It makes more sense now.
If you want to increase your production you may want to add a booster pump.

 

[KrisReef]

Hi all, what is your opinion on using 20-25 TDS rodi water for mixing and top off? I KNOW 0 TDS IS BEST. Curious if anyone is using around 20 TDS and hasn't noticed any negative side effects. Right now I am running a FOWLR system with corals possibly coming later down the line. I have only used 0 TDS rodi in my past tanks, I am just curious if anyone has or is using around 20ish TDS water with success. Please let me know your experiences with this, thanks

We used to use tap water for fish tanks and did not notice any problems.

When you start adding corals, you might want to do an ICP test to see what all you have in the soup before adding corals, but for FOWLR I wouldn't stress much about top off water, or mixing water at 20 TDS.