938 tds.....

[WhoDey64]

Filling up a new tank, only thing in it is a few Marco rocks and about an inch of corapet sand new as well. My RO unit is putting out 0 TDS verified with the unit on the RO and a handheld unit. Now for the crazy part, once the water hits the tank it has a TDS of 938... The tank is a new custom build and did not sit in a store, I have leak tested with tap water cleaned down with vinegar on a rag and wiped clean with an old T-shirt rag. I am truly stumped on what is causing this TDS spike.

Can anyone offer a guess?

 

[Jstdv8]

I don't suupose it would be as easy as you adding salt to that water thats now in the tank?

 

[WhoDey64]

No salt yet, I wish that was the case, just fresh ro water. Wondering if it's coming from the sand. It's extremely low dust but maybe it needs rinsed better.

 

[James404]

I would say it is the sand, once anything gets mixed in with your water its going to register TDS. As long as your water is reading 0 tds out of the RODI, I wouldn't worry.

 

[Blown76mav]

are you testing directly in the tank or removing water and testing in a clear glass? That will affect it.

 

[Misled]

You need to rinse the sand and the Marco rocks.

 

[WhoDey64]

I was testing directly in the tank, the TDS came way down fortunately. The rocks were fully cooked and rinsed but like others said it was probably the sand. Corapet does not cause a "sand storm" like other brands do and I have added it to other established tanks in the past without issue so I skipped the rinse this time around. Live and learn.

 

[sslak]

Dude..TDS is disolved solids.

Sand is a solid that containes many trace elements that will dissolve in water. There SHOULD be a high TDS reading once you put sand and rock in your water. It's hardly pure water anymore.

Water is the universal solvent, most substances on this earth will be dissolved into water given time.

You have nothing to worry about. TDS you're trying to avoid putting into your tank is the nitrates/copper/phosphates etc. that come through the pipes from the water company.

Relax and enjoy the new tank.

 

[scubasteve06]

Dude..TDS is disolved solids.

Sand is a solid that containes many trace elements that will dissolve in water. There SHOULD be a high TDS reading once you put sand and rock in your water. It's hardly pure water anymore.

Water is the universal solvent, most substances on this earth will be dissolved into water given time.

You have nothing to worry about. TDS you're trying to avoid putting into your tank is the nitrates/copper/phosphates etc. that come through the pipes from the water company.

Relax and enjoy the new tank.

Agreed 100% great post.

 

[travis32]

I'm curious how your getting 0 TDS from an RO unit though. Unless it's RODI in order to get 0 TDS you would have to have 100% rejection rate? Maybe I'm not understanding RO systems (most likely), but, RO by default allows some TDS through. That's the given nature of RO. My understanding is that's why DI is used to absorb what the RO gives out. Maybe the OP meant RODI. Don't know.

 

[The Velvet Sea]

If the starting tds of the water is low enough, and the membrane has a high enough rejection rate, it is entirely possible to have a tds meter read 0 from just RO. This type of situation, while uncommon, is not unheard of. That said, I'm guessing that the OP is equipped with RO and DI and to him I would advise, as many others have already, to not pay any attention to the tds of the water after it leaves storage.

 

[WhoDey64]

sslak, your right, it was a major brain fart.. Thanks for setting me straight

Travis, its a dual stage RO/DI unit, should have been more clear.