Comments: Great product to own.Installed it in 10 minutes.found out my incomming tap water was over 800PPM! I would highly recommed owning one!

Comments: Great little meter. Simple hook up and easy to read/use. Honestly I don't see myself using this often, but it is worth the money to check your filter once in awhile to make sure it is working. 185ppm in, 5ppm out for my house (97% rejection).

Comments: It seems to work great!!

Comments: I've had two five stage RO/DI units, but haven't had dual TDS meter on either units. Wow, what I difference you can tell easily what the water quality is coming in and out as production water. Take the guess work out of filter changing. I install the meter in 5 minutes, pretty straight forward. If you don't have one on your RO/DI unit you don't know what your missing. Highly recommended.

Comments: This iitem was easy to install within 5 minutes and gives me the information I'm looking for quickly and easily.

Comments: Only had for about a week so cannot speak to long term quality. Easy to install, easy to read, matched reading with friends handheld monitor perfectly.

Comments: This item is working well 1 week in.

Comments: Straight forward directions, very easy to install. It came up a half star short because it does NOT come with calibration fluid.

Comments: When I received the meter, I wasn't able to install it until a couple of weeks later. At that time, it seemed to work great! A couple of weeks after that, there was a couple of places on the display that quit working which makes it very difficult to get the actual reading. Better reliability would make this product worth the price.

Comments: Works great I have a reading of 150 ppm in and 000ppm out .Never new what my ppm from my tap water were before.Plus Iinstalled it before I changed my filters my readings were 150ppm in and 10ppm out.SO it does work.

Comments: Very accurate, now i can tell when to change my RODI unit

Comments: Although I have only had this unit for a short time, so far so good. It performs the way it is supposed to.

Comments: Very easy to install, no calibration needed. It's great to see how well your RO filter is working when comparing the input water and output water TDS (or at least it's nice to see that it's time to replace your filters).

Comments: very compact and performs excellently, easy to install and well worth the price, would recommend this meter to anyone using an r.o. system .

Comments: Installs in less than a minute. Very simple to use. No more hauling buckets of water for me.

Comments: Works great and a good price.

Comments: We needed this to monitor the water coming out of our RO/DI filter system. The product was easily installed and I had my first readings within a minute. Having two sensors is also great (you can toggle between "In", or the water going into the filter, and "out", which is the water that you are going to use) - they can also serve as a built-in double check. I got an initial reading of 249ppm for water going in to the final stages of filtration and 000 ppm coming out, which made me a little concerned that the "out" sensor may not be functioning. I switched the sensors, and then got readings of 250ppm before and 000ppm after, which confirmed the initial readings within 001ppm accuracy.
<br />We're pretty stoked to have RELIABLE RO/DI water on hand for our reef and amazon tanks. Especially me... I was the one who usually ended up carrying the 5 gallon jugs up 3 flights of stairs!!!

Comments: Works well, convenient that it can read both input and output of the RO/DI unit. Would be better if it had some sort of backlight, my unit is in a cabinet under the sink and it is a little dark and hard to see.

Comments: My LFS failed to tell me that I should change my filters when my resin cartridge changes color. (Instead he told me to change the filters when my output degrades - bad suggestion.. but perhaps they want addl business). I noticed an increase in hair algae finally got one of these bad boys. I replaced my filters, added one of these bad boys and don't use the RO/DI unit without confirming my level is still at 0. My hair algae is starting to go away and I expect it to disappear soon!

Comments: This little meter works great and is a snap to install. I found out my RO/DI unit is not giving me what it is suppose to I think I have to change the filters.

Comments: There is not an easier method of checking my membrane output. Simple switch gives me an in and out reading. Auto shut-off are a must for me, and this unit comes with it. 5 stars.

Comments: Great product! Very simple to hook up, took like 5min. My water source going in was 075 going out 000. Easy to read display also.

Comments: A must for anyone using ro/di.

Comments: product performs exactly as advertised. easy installation,would recommend this to anyone in need of a quality tds meter.

Comments: Quick easy hook up to my RO/DI unit. Hooked right to the front on my RO setup. Works great and lets me know instantly when I need to do maintenance on my RO.

Comments: Works great. Also simple to install, within minutes I had a reading.

Comments: BEFORE I PURCHASED THIS HM Digital In-line Dual TDS Meter, I WAS CONSTANTLY WONDERING IF THE WATER THAT MY RO UNIT WAS MAKING, WAS QUALITY WATER I WAS HAVING WATER PROBLEMS AND I THOUGHT THAT MAYBE THE FILTERS ON MY RO UNIT WERE BAD AND THE WATER IT WAS MAKING WAS NOT QUALITY 0 TDS WATER. I WAS PARANOID EVERY TIME I USED IT TO DO A WATER CHANGE. BUT NOW THAT I HAVE THIS METER I ALWAYS KNOW THAT THE WATER IS TOP NOTCH, NO MORE WORRYING OR WONDERING, ONE OF THE BEST PURCHASES I'VE MADE.

Comments: meter hooked up very easily and after reading what my household drinking water parameters where.i went out and got a water filter for the whole house. told all my friends about the meter and gave them your website thanks

Comments: Easy to fit and use, saves me having to worry about when to change out my RO and DI stages (saves me having to fork out dollars for filters I don't need)

Comments: This meter is simply fabulous. It was installed in two minutes and the readings are instant and clear. A must have for any RO/DI unit if you appreciate peace of mind.

Comments: Nice to have this piece of mind.....worth the dough.

Comments: It works beautifully!

Comments: This is a great product. It allow s me to tests my water at the push of a button. I know exactly the condition of my filters, and when to change them. Its great for monitoring my drinking water as well.

Comments: The meter was extremely easy to setup with good directions on installation and calibration. It is battery powered and the enclosure is screwed shut so I can't comment on the ease, or even if its possible, to change the batteries. The meter comes with adhesive velcro tape so you can stick it and remove it when necessary. I selected this over a pocket meter because I wanted a permanent solution to help determine a precise filter change schedule). 5 stars because its a great price and seems to be a great product out of the box.

Comments: I had an issue with my RODI. It wasn't working right and caused my tank to produce hair alage. I replaced the RODI system and added the HM Digital In-Line TDS Meter. Now when I want to check the water quality all I have to do is push a button.This product is a must for any one with an RO system.

Comments: The only challenge faced with the installation was the fact that the hook up to my RO unit intake is/was a 3/8" and both of these fittings are for 1/4" lines. I picked up a 3/8" to 1/4" adaptor and used a spare 1/4" 90' elbow to complete the installation.
<br />After installation, works like a champ.
<br />Only improvement I could see would be to accommodate a 3/8

Comments: If you already have an RO/DI or just DI system for generating your water, you probably don't check the output quality of the system often enough. I know I didn't. I trusted the color changing resin to tell me when to change. I have a hand TDS meter but I just rarely used it.
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<br />Now I check it every time I run the system. This meter takes about 5 minutes to install--just turn off incoming water, cut the 1/4"supply line and the final purified water line, insert the speedfit Tees with the meters, connect the wires to the small display unit. That's it. The velcro tape is the most technical part of the job.
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<br />Just press a button to turn the display on (has auto-off to save batteries) and slide the switch between incoming and outgoing. I confirmed that my incoming water runs between 250 and 320 ppm (which I kind of knew, but didn't check once the filter system was up and running) and my output with new DI resin is rock solid 0. What I learned new is that the quality of my output water started to degrade before the two DI resin cannisters were completely brown. By the time the second was actually fully changed, the water was coming out with higher TDS readings than the incoming city water!
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<br />This is a great $40 addition to quickly and easily verify that the water you are using for top-off is actually as pure as you think it is.