Jack,
It looks like you are measuring TDS and finding that it changes with temperature. This is normal for a TDS meter that doesn't have temperature compensation. For example the TDS-EZ made by HM Digital will show a much lower TDS in cold water, while the TDS-3 made also by HM Digital will not vary with temperature as it has built in compensation.
Hardness and TDS are not really synonymous. General Hardness (GH) is a more specific measurement than TDS.
Jack, as you are probably aware, pH can also vary with temperature (see: http://reagecon.com/pdf/technicalpap...-_TSP-01-2.pdf) , so you might want to try the following experiment in a 5 gallon bucket. Mix the appropriate ratio of hot to cold water to get close to the target temperature of water for your tank. (This will also help you to determine the ratio that you might need for a larger reservoir.) Measure pH and compare that value to the temperature of the water in your tank. I'm assuming that the aquarium temperature is already set where you want it for your fish. If they are the same or within 0.1 pH unit, you probably don't need to age your water. One caveat is that the aquarium needs to be completely cycled, since addition of ammonia to keep the cycle going will artificially raise the pH.
Jack, just to be clear, there is a very big difference between hardness (GH) and TDS. Hardness is essentially measuring the level of divalent cations (usually calcium and magnesium ions) in water. Those are the ones that interact with soap components to give the soap scum that everyone hates. TDS is a measurement of all of the ions in a water sample, both mono-and divalent. If you run water through a water softener, you will soften the water by exchanging the divalent cations for sodium or potassium ions. The amount of hardness changes dramatically but the TDS will not change significantly, since you have only substituted one chemical species for another.
Ahh my bad guys,
didn't know that they were significantly different. Thought this because a lot of the things I read were with measurements in hardness or tds and I thought it was similar as people didn't specify. But now I understand. So normally, TDS measurements is used more often than hardness when people talk about discus liking softer water. So what exactly is the point of a TDS meter when it measures both mono- and divalent cations if it can't detect the actual water hardness? vs say a hardness test kit/strips?
The one I have is the TDS-EZ. So what exactly is the difference between TDS-EZ and TDS-3? Because the prices for the -3 are cheaper than the -ez?
So at the time when I bought it, I thought the one that was a bit more expensive would be the better one. So is the tds-3 better in this regard to temperature?
And thanks for the clarification
I really appreciate all the help, knowledge, and love from you guys!!
The word "hardness" can be confusing, so when reporting water hardness it is important to specify whether you are using units of GH (general hardness, mainly calcium and magnesium) or TDS, which is conductivity converted to parts per million of a salt. In freshwater the two measurements usually track each other, except when you have a water softener. Water softeners lower the GH while keeping the TDS about the same. "Softened" water is better for plumbing and soap, but if you are a fish it is still hard water.
Most aquarists use TDS meters as an indicator of how soft the water is because they are fast and easy to use. The TDS-EZ meter you have is fine as long as you consistently measure water at tank temperature. You would think the one with the built-in thermometer and temp compensation would cost more but it doesn't. Temperature by the way has a much bigger effect on TDS measurement than on pH measurement. When you calibrate your pH meter it is good enough if the calibration fluid is within 8 or 10 degrees Fahrenheit of the water you test.
Here is the best article I have seen on TDS:
http://reefkeeping.com/issues/2004-0...ture/index.php
Thanks dan and dudley for the explanations really helpful and useful information!!
So is GH measured with a kit? and is this measurement important to have?
And I don't quite get the part where "Softened water" is not really a difference for fish. So soft/hard water doesn't really matter for discus? or doesn't make that much of a difference?
Since I eventually want to breed discus and all that fun stuff and I've read in a lot of places that "soft" is preferred. maybe through an RO system?
I think its good to know your water, especially its pH swing and TDS, but it doesn't hurt to also know the GH and KH (carbonate hardness, or alkalinity). Here is the test kit I use for those:
http://www.amazon.com/API-GH-KH-Test-Kit/dp/B003SNCHMA
The KH is a measure of the water's capacity to keep a stable pH. With frequent water changes this is not a concern unless the KH is extremely low.
For breeding most people use a mix of RO and tap for softer water. If you don't have a water softener then the matter is simpler. If you do then Dudley can explain the part about soft/hard water better than I can. My situation is not typical, I'm forced to use RO for everything because of high nitrates in the well water and so I don't mix any in with the RO. Nitrates in city water are not that common but should be tested for just in case.
Sounds good. Bought
Now I need to do some research on meds just in case and get some on hand.
what are some of the important ones that is like a must have?
Yeah and I don't have a RO system rn so Id have to get one if it comes to that.
Hello Jack from Crestline OH. How is the fish keeping coming along?