TDS testing my LFS RO/DI - what can be in it?

Reefin' Alaska · Oct 20, 2020

I have recently been struggling with some diatoms that seem to come back and come back. I have done a bit of research and learned that silicate in the water cause the diatoms. I went today to have my LFS RO/DI water tested at a local water equipment supplier.

The water tested at 85 TDS.

Needless to say, I won't be going back there to get water. However, I live in Alaska, RO water is readily available, but not DI.

When TDS is tested, could that number contain phosphates as well? That would explain why my Hanna kits read so high, even though my bioload is 2 fish and some cleaning crew, and I do not feed heavy. With that question, can I use just simple RO water? It's my understanding that it's 95%-98% pure simply with that. Is DI necessary? I live in an apartment, faucets are weird they are not your standard connections to use something like an RO Buddy, and it's Alaska, it's not like a hose outlet is ready available in October. Lol.

dbowman5 · Oct 20, 2020

i would suggest:
RODI water has 0 TDS in its finest condition. as soon as it is in contact with something, anything on that something is flushed into the water. anything that can be dissolved in water will start to dissolve. these actions will add to TDS readings. RO has more impurities than RODI but it is better than tap water.
I would ask the lfs to test their water for you to confirm your results. it could be in error or the LFS may have had an issue.
it might make sense to have a TDS meter of your own. Are you really ready to burn a supplier that you may be able to work with? You were buying RODI; that is what you were paying for, I would wonder if it was a mistake that they would be happy to hear about rather than lose customers and get a bad reputation.
as far as what the TDS consists of, have you used your Hanna tests on the water before you mix it and then before you add it to your tank?
BTW visited your city. very impressed!

Reefin' Alaska · Oct 20, 2020

dbowman5 said:
i would suggest:
RODI water has 0 TDS in its finest condition. as soon as it is in contact with something, anything on that something is flushed into the water. anything that can be dissolved in water will start to dissolve. these actions will add to TDS readings. RO has more impurities than RODI but it is better than tap water.
I would ask the lfs to test their water for you to confirm your results. it could be in error or the LFS may have had an issue.
it might make sense to have a TDS meter of your own. Are you really ready to burn a supplier that you may be able to work with? You were buying RODI; that is what you were paying for, I would wonder if it was a mistake that they would be happy to hear about rather than lose customers and get a bad reputation.
as far as what the TDS consists of, have you used your Hanna tests on the water before you mix it and then before you add it to your tank?
BTW visited your city. very impressed!

I didn't ask the local store to test the TDS of their water, but I do have my suspicions based on what I've seen.

I have not used the Hanna tests on the source water, I guess that's the next step. Having said that, this tank is a over a year old, I've been getting water from the same source and haven't had any of these problems until recently. Nothing has changed recently, either. Everything is consistent. My test schedules are consistent unless I'm gone for work. I did ask the LFS if they've changed membranes recently, their answer was "We use the same water in our system and we haven't had any issues, so no." Everything considered, I think you can understand my concern. I also ran GFO for about a month, and phosphates were still elevated. It's been an on going issue since August - when the diatoms started as well.

It is a local business, the only one in this space, and it's the only one we've ever had that was smart enough to invest right to sustain this type of business here. 3 big grow tanks that they frag from colonies, and then a series of frag tanks to sell from. So I don't want to burn that bridge, like you said.

The water tested with a TDS meter, in the 3G container I filled 10 mins prior to that. I also took some out of the 5G container I filled at the same time and that tested at 84. The water supply store is 1 red light and a left hand turn from my LFS.

It's cold, but it sure is beautiful this time of year here. =)

Viking_Reefing · Oct 20, 2020

The best solution is to get your own rodi filter. That way YOU are in control of what’s going in to your tank

Reefin' Alaska · Oct 20, 2020

MichaelE said:
The best solution is to get your own rodi filter. That way YOU are in control of what’s going in to your tank

Correct. But I live in an apartment and have these fancy Delta show faucet things, there aren't any faucet hook ups available to me. It is what it is.

notsobigtime · Oct 20, 2020

Kurant said:
Correct. But I live in an apartment and have these fancy Delta show faucet things, there aren't any faucet hook ups available to me. It is what it is.

Do you have a laundry room/space? you can hook one up to the cold tap for the washing machine.

Tamberav · Oct 20, 2020

Kurant said:
Correct. But I live in an apartment and have these fancy Delta show faucet things, there aren't any faucet hook ups available to me. It is what it is.

Hook it up under the sink, that is how it is hooked up in my apartment. I just bought a part that screws between the line and T's to the RODI. When I move, I just unscrew it. No permanent change.

Reefin' Alaska · Oct 20, 2020

Tamberav said:
Hook it up under the sink, that is how it is hooked up in my apartment. I just bought a part that screws between the line and T's to the RODI. When I move, I just unscrew it. No permanent change.

Can you share where you got the part?

piranhaman00 · Oct 20, 2020

Was the reservoir used to fill clean? Even a drop of salt water will create ***** TDS.

Reefin' Alaska · Oct 20, 2020

piranhaman00 said:
Was the reservoir used to fill clean? Even a drop of salt water will create ***** TDS.

It looks clean, from the outside. Who knows. Lol.

Tamberav · Oct 20, 2020

Kurant said:
Can you share where you got the part?

Mur-Lok EZ Angle Stop Adapter

Mur-lok EZ Angle Stop Adapters (faucet adapter) directly connect an RO unit to the household water supply. It installs under the sink, inline after the shut-off valve. This clean, out of the way installation leaves faucets free for other use. Mur-lok EZ Angle Stop Adapter 1/4" 3/8" Male...

www.bulkreefsupply.com

John Guest 1/4 in. Push-To-Connect x 3/8 in. Female Compression x 3/8 in. Compression Polypropylene Valve Fitting 803389 - The Home Depot

The John Guest 3/8 in. Comp x 1/4 in. O.D. Push-to-Connect Angle Stop Adapter Valve is manufactured from white polypropylene and equipped with EPDM O-rings utilizing John Guest's push-fit technology to

www.homedepot.com

Be sure to use teflon tape.

Randy Holmes-Farley · Oct 21, 2020

Kurant said:
When TDS is tested, could that number contain phosphates as well? That would explain why my Hanna kits read so high, even though my bioload is 2 fish and some cleaning crew, and I do not feed heavy. With that question, can I use just simple RO water? It's my understanding that it's 95%-98% pure simply with that. Is DI necessary? I live in an apartment, faucets are weird they are not your standard connections to use something like an RO Buddy, and it's Alaska, it's not like a hose outlet is ready available in October. Lol.

Yes, but I'd be more worried about copper.

Reefin' Alaska · Oct 21, 2020

Randy Holmes-Farley said:
Yes, but I'd be more worried about copper.

I just ordered a copper test today. Couldn't find one locally.

If there is copper, what can I do?

Reefin' Alaska · Oct 21, 2020

Randy Holmes-Farley said:
Yes, but I'd be more worried about copper.

Oh and part 2, until my RO/DI gets here through my LFS, is it okay to use just standard RO? It might be a few weeks since it comes by truck/boat.

Randy Holmes-Farley · Oct 22, 2020

Kurant said:
I just ordered a copper test today. Couldn't find one locally.

If there is copper, what can I do?

Won't be useful. Way too high of a lower limit on any kit. ICP can be useful.

Randy Holmes-Farley · Oct 22, 2020

Kurant said:
Oh and part 2, until my RO/DI gets here through my LFS, is it okay to use just standard RO? It might be a few weeks since it comes by truck/boat.

RO water is better than tap, and often is adequate.

If your water supply uses chloramine, there will be ammonia in it. Check with them.