Top tds meter to buy?

[Tcook]

100$ budget. Whats a good tds meter to buy? For absolute accuracy?

Absolute accuracy beyond the simple HM digital units is not required for the reef tank. Is this a laboratory setting you will be using this for? If so you can check with Milli-Q

 

[Spare time]

I use the inline HM one

 

[kristianosayer]

I wonder if it's possible there is something leeching from the plastic. Only throwing this out there as I've seen another thread before on brute cans and tds

Speed Test​

 

[Croftsy]

I use this on my system. Accuracy is +- 2%

LDM-100R Dual Probe Rejection Monitor

At Buckeye Hydro we specialize in providing the highest quality water filtration systems and accessories for every potential need.

www.buckeyehydro.com

How have you found your hm tds monitor? Where it work out the wastage percentage is that how much is good or wasted?

 

[KStatefan]

How have you found your hm tds monitor? Where it work out the wastage percentage is that how much is good or wasted?

No it is the rejection rate of the membrane

 

[EricR]

How have you found your hm tds monitor? Where it work out the wastage percentage is that how much is good or wasted?

I think it would be cool to have some kind of flow monitor on RO waste (brine?) and output (permeate),,, rather than timing/measuring each to calculate ratio,,, just for quick glance at when you should change restrictor size at different times of the year (different source water temperatures), but have never seen one.

 

[Croftsy]

No it is the rejection rate of the membrane

Okay for example if it was 80% and you had 20 litre of ro water would the Rejection be 80 litres?
Trying to get my head around it. Has it been good bit of kit?

 

[Randy Holmes-Farley]

Okay for example if it was 80% and you had 20 litre of ro water would the Rejection be 80 litres?
Trying to get my head around it. Has it been good bit of kit?

Rejection rate has to do with the portion of salts getting through the membrane.

90% rejection means 10% gets through the membrane.

If incoming water is 100 ppm TDS and you have 90% rejection, the water getting through the membrane has 10 ppm TDS.

 

[Croftsy]

Yeah I get it now it just does the calculation for you and give a percentage. I thought it might be the volume of water but as someone said they hadn’t seen one before that does that. Might just got the HM digital DM-3 model

 

[KStatefan]

Okay for example if it was 80% and you had 20 litre of ro water would the Rejection be 80 litres?
Trying to get my head around it. Has it been good bit of kit?

It is just measuring the tds of the source water in and permeate out of the membrane and then calculating the salt rejection rate