Water TDS measurements - Why so high ???

[kimha]

Hello experts,

I just bought a HM TDS meter to measure my aquarium water quality. Please let me know if the numbers look normal.

Water from faucet - 448 ppm
Water after processed by the RO/DI unit - 0 ppm
Water to be discarded from RO/DI unit - 615 ppm

Water from the fish tank FOWLR - 950 ppm.

I was expecting the water from fish tank to have a lower value than the water from the faucet. Why is it so high? is it normal?

 

[ngvu111]

I never measure tank water so I don't know what to expect but I think it's understandable to have high tds from tank water because of all the stuff we put in the synthetic salt plus the fish poops and god knows what else there can be there.... If your faucet water is closed to 500, the di will get burnt pretty fast.

 

[Henry760]

Total Dissolved Solids.. sounds about right in your tank as ngvu mentioned(salt, waste etc). . Interesting about the waste water having a higher tds.. I install water filtration systems commercial and residential and Never tested waste water

 

[KarL]

If the display tank water reads at 900ppm, why do some freak out when their RODI output readings are anything higher than "0"?

 

[AddictedtoSalt]

If the display tank water reads at 900ppm, why do some freak out when their RODI output readings are anything higher than "0"?

Maybe because the the ro water could have chlorine, copper , and other nasty not good for your tank stuff in it that is showing as tds?
I dont know for sure, but it sounds good to me.

 

[xmas_one]

The water in your tank is likely closer to 35000ppm, aka 35ppt, aka an SG of 1.026, and that's just from the salt.

 

[Igarc009]

High TDS doesn't kill corals. I know of a pretty big reef store that uses water with TDS in the hundreds.

 

[KarL]

I guess that means I can hold off on changing out my filters

 

[lurking]

The dissolved solids that an RODI removes can be any number of harmful elements. Things that contribute to algae, harm fish etc. These need to be removed first so we know that we have good clean water going into our systems. The salts and minerals and fish waste will increase the tds value back up but not necessarily with bad stuff.

 

[Igarc009]

I guess that means I can hold off on changing out my filters

As long as you don't have sps you'll be fine.

 

[Igarc009]

Double post

 

[pgr11]

The dissolved solids that an RODI removes can be any number of harmful elements. Things that contribute to algae, harm fish etc. These need to be removed first so we know that we have good clean water going into our systems. The salts and minerals and fish waste will increase the tds value back up but not necessarily with bad stuff.

^^^^ this. You can see the difference if you take and test your rodi water straight out of your unit and its 0. Now take that same water and place it in a container that has only held fresh saltwater. The # will be high due to what in the salt, but its not bad for anything