New ro unit and tds issues - Page 3

fishkeeprian · 08/19/2018, 11:57 AM

Quote:

Originally Posted by mcgyvr

You seem to have the ro holders waste line and ro out lines switched...

Doh, I've took my reading from the waste line instead of the product line. I've started the unit up again I will retest. Thanks for the prompt.

fishkeeprian · 08/19/2018, 12:15 PM

Quote:

Originally Posted by mcgyvr

Did you post tds results again after the new membrane/di?
Incoming...post ro...post di?

OK now the readings are;

In is 238ppm
Before Di is 8ppm
After is 2ppm

mcgyvr · 08/19/2018, 12:34 PM

Quote:

Originally Posted by fishkeeprian

OK now the readings are;

In is 238ppm
Before Di is 8ppm
After is 2ppm

Did you actually have the system hooked up backwards this whole time or just tapped the wrong lines for those readings?
If you did have it switched the whole time that would explain a lot..

When you are taking readings of the 2ppm water are you letting it run/drain for a couple minutes first then filling up a CLEAN glass and immediately sampling as soon as you get like 2cm in the glass?

fishkeeprian · 08/19/2018, 12:53 PM

Quote:

Originally Posted by mcgyvr

Did you actually have the system hooked up backwards this whole time or just tapped the wrong lines for those readings?
If you did have it switched the whole time that would explain a lot..

When you are taking readings of the 2ppm water are you letting it run/drain for a couple minutes first then filling up a CLEAN glass and immediately sampling as soon as you get like 2cm in the glass?

It's been hooked up perfect. I just tested the water wrong that one time. When I start the unit up after a 10min flush it normally starts at around 4/5ppm then after a couple of litres it runs down to 2ppm but will go no lower. Once its hit 2ppm I tested the water in a clean cup as you say.

I worked out I'm get a 96.4% rejection rate from the membrane is that right? Why won't it zero out?

mcgyvr · 08/19/2018, 01:02 PM

Tds meter off some..or something off with di stage...

fishkeeprian · 08/19/2018, 01:23 PM

Quote:

Originally Posted by mcgyvr

Tds meter off some..or something off with di stage...

So what would be you next step? Calibrating the TDS metre?

mcgyvr · 08/19/2018, 01:54 PM

Quote:

Originally Posted by fishkeeprian

So what would be you next step? Calibrating the TDS metre?

Ensuring the measurement device is accurate is certainly important

Uncle99 · 08/19/2018, 02:15 PM

Don't take reading from glass or cup....
Put your meter in the holding tank and read.....bet ya it's zero.
The larger sample for me always reads 1,2,3,2,1,1,2,1 and the cup reads, 5-7.

The things that cause small variation is cheap meter, unclean probes cups or small sample sizes. Also caps that are not tight can give the same result.

Be happy with 2 TDS, use for a month or two, check each time ya make water.

I am happy with things when they are producing what I need, your reject rate for incoming is fine.

mmx01 · 08/19/2018, 02:40 PM

Sorry but 300-400 at the source is not that high to see anything but 0 at the output...

What is your DI cartridge? Is it a tube with 2 blue caps which is typical here in the EU? Make sure you load it full and tight so that no water passes through the gaps when you lay it horizontal. It has to be packed tight.

From 300-400 at the source you get 0 even with a cheap membrane and DI resin.

BR,
M

Uncle99 · 08/19/2018, 06:09 PM

Most meters are not that accurate.
But of course, feel free to work that TDS to zero.
I settled for 1-3 ppm, 27 yeas ago and never had a problem.
Actually, my corals seemed to do better in the 1-3ppm range.
It's like chasing PH, ya I want 8.3, but I will settle for 7.8

wrott · 08/19/2018, 07:41 PM

Quote:

Originally Posted by Uncle99

Most meters are not that accurate.
But of course, feel free to work that TDS to zero.
I settled for 1-3 ppm, 27 yeas ago and never had a problem.
Actually, my corals seemed to do better in the 1-3ppm range.
It's like chasing PH, ya I want 8.3, but I will settle for 7.8

Exactly,
If TDS increases after 200-300g of product, then you have a problem--using the same TDS monitor that may be too sensitive initially.
Just check after a couple hundred gallons.

fishkeeprian · 08/20/2018, 04:26 AM

I have spoken with the manufacturer and they are sending out a new complete unit under warranty.

fishkeeprian · 08/31/2018, 02:08 AM

Unit number three now.

This was tested by the manufacturer prior to leaving and I am pleased to say after getting the unit is now running at 0TDS. HAPPY DAYS

https://www.dropbox.com/s/fm4pd9zdht...84159.jpg?dl=0

08/19/2018, 01:02 PM	#55
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Tds meter off some..or something off with di stage... __________________ Who me?

08/20/2018, 04:26 AM	#62
fishkeeprian Registered Member Join Date: Feb 2016 Location: England, Earl Shilton Posts: 1,452	I have spoken with the manufacturer and they are sending out a new complete unit under warranty. __________________ If in doubt ask!

08/31/2018, 02:08 AM	#63
fishkeeprian Registered Member Join Date: Feb 2016 Location: England, Earl Shilton Posts: 1,452	Unit number three now. This was tested by the manufacturer prior to leaving and I am pleased to say after getting the unit is now running at 0TDS. HAPPY DAYS https://www.dropbox.com/s/fm4pd9zdht...84159.jpg?dl=0 __________________ If in doubt ask!

08/19/2018, 02:15 PM	#58
Uncle99 Crab Free Zone Join Date: Sep 2017 Location: Ontario, Canada Posts: 2,906	Don't take reading from glass or cup.... Put your meter in the holding tank and read.....bet ya it's zero. The larger sample for me always reads 1,2,3,2,1,1,2,1 and the cup reads, 5-7. The things that cause small variation is cheap meter, unclean probes cups or small sample sizes. Also caps that are not tight can give the same result. Be happy with 2 TDS, use for a month or two, check each time ya make water. I am happy with things when they are producing what I need, your reject rate for incoming is fine.

08/19/2018, 02:40 PM	#59
mmx01 Registered Member Join Date: Nov 2017 Posts: 17	Sorry but 300-400 at the source is not that high to see anything but 0 at the output... What is your DI cartridge? Is it a tube with 2 blue caps which is typical here in the EU? Make sure you load it full and tight so that no water passes through the gaps when you lay it horizontal. It has to be packed tight. From 300-400 at the source you get 0 even with a cheap membrane and DI resin. BR, M

08/19/2018, 06:09 PM	#60
Uncle99 Crab Free Zone Join Date: Sep 2017 Location: Ontario, Canada Posts: 2,906	Most meters are not that accurate. But of course, feel free to work that TDS to zero. I settled for 1-3 ppm, 27 yeas ago and never had a problem. Actually, my corals seemed to do better in the 1-3ppm range. It's like chasing PH, ya I want 8.3, but I will settle for 7.8