Don.Julio91
Supporting Member
So did you calibrate with distilled/ RODI water to 0 reading or did you use calibration fluid to 35ppt/1.026 readings?
Beginner reefer seeking advice
- Thread starter ryanraff
- Start date
H2OPlayar
Supporting Member
Tap water is rarely 1.000, use RO/DI from a known good system for calibration.
elee901
Supporting Member
ahh okay yeah I see someone else mentioned that. Shoot my readings might be off then. I'll compare against RODI once I get my hands on some.
MichaelB
Supporting Member
I think you wanna use distilled water for calibration, tap can have sediments in it making calibration efforts in precise. Distilled lets you know there is zero sediments/ additives.
Distilled you can grab a gallon at just about any store.
H2OPlayar
Supporting Member
Distilled is not guaranteed to be 0 TDS and I wouldn't use it for calibration. It might be fine for top off but you don't know without testing what is in it. You can get RODI from any lfs if you don't have a system yourself yet.
I used to use a refractometer and calibrated with 35ppt solution, but I would have to re-calibrate it more than I would like and therefore didn't really trust it. Also, if you use calibration solution, that can get out of whack over time due to evaporation, so for me that's two things I can't really trust.
I now use a Tropic Marin Hydrometer and there's no need to calibrate as long as you take into consideration any temperature differences. I have a small tank like you, so it's not deep enough for the hydrometer, but I fill a 500ml graduated cylinder with 450ml of tank water, put the hydrometer in the cylinder, spin it to remove any bubbles, then let it to settle to get my salinity measurement. I can get my salinity checked in the same amount of time as the refractometer, if you count the 45-ish wait for the refractometer's automatic temperature compensation, and way faster than if I had to calibrate my refractometer.
I now use a Tropic Marin Hydrometer and there's no need to calibrate as long as you take into consideration any temperature differences. I have a small tank like you, so it's not deep enough for the hydrometer, but I fill a 500ml graduated cylinder with 450ml of tank water, put the hydrometer in the cylinder, spin it to remove any bubbles, then let it to settle to get my salinity measurement. I can get my salinity checked in the same amount of time as the refractometer, if you count the 45-ish wait for the refractometer's automatic temperature compensation, and way faster than if I had to calibrate my refractometer.
MichaelB
Supporting Member
I honestly didn't know distilled could not have 0 tds. I tested one type from safeway several months back it read zero tds when I was using it for ato water.
So if i'm understanding you right, am I right in assuming your implying that rodi water is overall more pure than distilled?
I always kinda thought they were about the same, and it was just not practical to apply the distilllation proccess of water at home. Hence people used rodi filters.
MichaelB
Supporting Member
I have a refrac from when I first started out but haven't used anything else since I got the hanna one.
In this hobby nothing has to be spot on. Close is good enough. We chase numbers too much. Stability is your friend. Corals and fish will adapt as long as it’s not way off.