How do I test for TDS in my source water

[ramullinax]

I just hooked up my shiny new RO/DI unit last night and turned the water on. I let it run for about 8 hours and got between 35 - 40 gallons of good water. That seems high to me for a system that is rated 75 gpd. I want to test the water before adding it to my aquariums. What's the best way to test for TDS?

Thanks,

Ryan

[shag26272]

TDS meter

[ramullinax]

Home Depot, Lowes or order online?

[shag26272]

I got mine on ebay its a Milwaukee brand, i doubt you can find it at lowes or HD most places that sell the RO/DI units have them also

[reef_doug]

Online, many places like ReefGeek, Marine Depot, etc.

I prefer the handheld meters vs. inline version, allows you to check all the waters very easy.

I have the Hanna Marine TDS1. I think it cost around $35.00

[collins]

if it is producing too much water, it may be that the RO cartridge isn't seated all the way. It is usually a tight fit.

[jeffbrig]

Ryan, I have a unit with a 75gpd membrane that produces 110-120gpd at 0tds. Membranes are rated at 70 degrees and 50psi. Warmer water temps speed production, as does increased tap pressure. My tap water is ~75 and 75-80psi, which is right in line if you look at the production charts for a dow filmtec membrane.

[ramullinax]

Thanks Jeff!

[AZDesertRat]

PM me. I am off Bell Rd & I-17 and have a TDS meter you can borrow. I can also give you pointers on what to get and where.
This time of year you should be getting a little less than the rated flow here in Phoenix due to lower water temperatures, mine is running 58 to 64. The meter also does temp so it will tell you.