TDS testing (1 Viewer)

[oldmantran]

We are usually so hung up on ensuring that our water changes are done with 0 TDS water. Has anyone bothered measuring the TDS level in your tank? I did yesterday and it said 857 x5 (or 10). I was so shocked at how high the number was I can't even recall what the multiplier was. So the question that is begged to be asked is: How much difference does it make to make a 10% water change with 0 TDS, when you're putting it in with 90% volume with an enormous amount of TDS?

Or am I completely missing something in my system that is supposed to be eliminating a majority of my TDS in the tank?

 

[flipside]

Yeah... the TDS you are measuring in your salt water are dissolved substances that you actually want in there. The stuff you are removing from the tap are dissolved solids that you don't want in there. You're not missing anything, and anyone should expect to have extremely high TDS values in their tank. It "should" be desirable substances, though. While your RO/DI unit is removing "some" substances that are beneficial to your tank, it's best to start with a clean slate, so to speak.

 

[spongebob281]

That makes perfect sense. I was appalled to see my TDS reading hovering near beyond reading range. On a side note I whipped out my meter just to see what my RO unit and the water mills near me read. They both came in at 11 and 17 respectively. Like Whoa!!!

 

[flipside]

That's really not that bad, considering. That's d@mn great drinking water! And, that's what it's intended for. My RO spigot, at my house, is around the same. The DI gets all the other junk, but I only use the sink unit for emergencies and drinking water. TDS should be off the chart in the actual tank... It just needs to be sterile before you add your salt mix... well, as close to 0ppm as possible.

FWIW, I've added 40-50ppm water to my topoff before, to no "real" ill-effect. I don't recommend it long-term, but when in a pinch, it shouldn't kill everything off (why risk it though, right?). About the worse I've seen is an algae bloom, but that's reversible with a bit of patience.

 

[CBBSteve]

Hi, oldmantran.
I don't mean to be critical here, but measuring TDS in salt water is a useless exercise. TDS is Total Dissolved Solids and that includes the solids - salt - you put in your tank. Salinity or specific gravity of your tank water is a more valuable number.

The reason we're all excited about 0 TDS makeup water is that it allows us to start with a known clean water and then add the required amount of minerals. That way we can reliably control the quality of our water.

good luck,
Steve

 

[ange062]

That's really not that bad, considering. That's d@mn great drinking water! And, that's what it's intended for. My RO spigot, at my house, is around the same. The DI gets all the other junk, but I only use the sink unit for emergencies and drinking water. TDS should be off the chart in the actual tank... It just needs to be sterile before you add your salt mix... well, as close to 0ppm as possible.

FWIW, I've added 40-50ppm water to my topoff before, to no "real" ill-effect. I don't recommend it long-term, but when in a pinch, it shouldn't kill everything off (why risk it though, right?). About the worse I've seen is an algae bloom, but that's reversible with a bit of patience.

Using tap water and dechlorinator lead to the overnight demise of Steve Weasts 800g monster that's among my favorite tanks of all time. I think you are right about not risking it, why play with fire if you don't want to get burned?

http://www.oregonreef.com/sub_gallery.htm

 

[spongebob281]

Didn't see it mention anywhere on that site. I highly doubt it unless his tap output is a gazillion ppm.

 

[ange062]

Didn't see it mention anywhere on that site. I highly doubt it unless his tap output is a gazillion ppm.

All the info is here:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1080179

Low TDS tapwater, but thinks it was a bad or expired batch of dechlor.

 

[NarnyTheGreat]

Wow thats HORRIBLE! I would have cried.... for days.