RO/DI TDS question

[archgetty]

After a move, I have no way to drain the excess water produced by my RO/DI. So I'm thinking about trying bypassing the membrane and running my tap water through the sediment, 2 carbon blocks, and 2 resin cartridges. Looks like I'm getting 4-5ppm TDS output that way. Is that acceptable for topping off my reef tank?
Thanks for any help!

 

[StatelineReefer]

I think the question would be what's IN the 4-5 TDS...

Copper? Arsenic? Lead? Nitrates? Chloramines?

 

[dwest]

After a move, I have no way to drain the excess water produced by my RO/DI. So I'm thinking about trying bypassing the membrane and running my tap water through the sediment, 2 carbon blocks, and 2 resin cartridges. Looks like I'm getting 4-5ppm TDS output that way. Is that acceptable for topping off my reef tank?
Thanks for any help!

Im guessing you are going to go through DI real fast.

 

[Mr. Mojo Rising]

4 or 5 is so insignificant, but 0 is still better

 

[Randy Holmes-Farley Verified Community Expert]

Bypassing the DI can result in substantial ammonia in the water if your water supply uses chloramine.

TDS alone doesn't say what is in the water. In most cases, a few ppm TDS after an RO is OK, but it will not always be OK because something like copper may be too high still.

 

[MamaMolo]

Why not just drain excess water in the sink and not bypass membrane. You can also drain it into a bucket and water ur house plants lol. 0 tds is better

 

[theMeat]

Like others have said we don’t know what’s in the 4-5 tds, and would be curious to know the tds is going into the di resin. If it’s high the resin is removing a lot and won’t last long and will get expensive

 

[JTP424]

I'd pick up something like this to give it a test
Anytime my PPM is above 2 I give it a test with one of these to make sure it isn't something bad for my tanks.

 

[archgetty]

Bypassing the DI can result in substantial ammonia in the water if your water supply uses chloramine.

TDS alone doesn't say what is in the water. In most cases, a few ppm TDS after an RO is OK, but it will not always be OK because something like copper may be too high still.

I would have thought the 2 1-micron carbon block filters would catch the chloramine?

 

[Randy Holmes-Farley Verified Community Expert]

I would have thought the 2 1-micron carbon block filters would catch the chloramine?

Carbon blocks break chloramine into chloride and ammonia, both of which remain in the water.

 

[nereefpat]

There has to be some way to drain the reject water from the membrane. Just flop a line into the sink, or run a line to a floor drain. Worst case scenario is that you have to drill a hole into a sink drain.

 

[NormanB]

Carbon blocks break chloramine into chloride and ammonia, both of which remain in the water.

Until when?

 

[Borat]

As we say in Kazakistan - water with less than 30% human solids is good for everyone, including human peoples, fish, and donkeys!

 

[NormanB]

As we say in Kazakistan - water with less than 30% human solids is good for everyone, including human peoples, fish, and donkeys!

Only human peoples? What about the rest of us????

 

[nuxx Verified Sponsor]

As we say in Kazakistan - water with less than 30% human solids is good for everyone, including human peoples, fish, and donkeys!

Niiiiice

 

[Randy Holmes-Farley Verified Community Expert]

Until when?

Until the sun expands, encompassing the earth and burning it all up.

A carbon block doesn't remove chloride or ammonia.

They are partly (mostly) rejected by the RO membrane, and the remainder will be bound by the DI.

I discuss these issues in detail in these articles:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com

Chloramine and the Reef Aquarium - Reefkeeping.com

 

[KStatefan]

After a move, I have no way to drain the excess water produced by my RO/DI. So I'm thinking about trying bypassing the membrane and running my tap water through the sediment, 2 carbon blocks, and 2 resin cartridges. Looks like I'm getting 4-5ppm TDS output that way. Is that acceptable for topping off my reef tank?
Thanks for any help!

You will need to slow down to flow to get enough contact time. If you just bypassed the membrane it would guess the flow is to fast.

There are people that run this way but most likely finding a way to run the membrane would be the best option.

 

[NormanB]

Until the sun expands, encompassing the earth and burning it all up.

A carbon block doesn't remove chloride or ammonia.

They are partly (mostly) rejected by the RO membrane, and the remainder will be bound by the DI.

I discuss these issues in detail in these articles:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com

Chloramine and the Reef Aquarium - Reefkeeping.com

LOL

Thanks Randy!!!

 

[Randy Holmes-Farley Verified Community Expert]

LOL

Thanks Randy!!!

You're welcome.

Happy Reefing.