gH question

[al4n]

Hi,

So i did the test..

kH test first which took three drops to turn blue to yellow. 50ppm?

Next gH test, it took thirteen drops to turn from yellow to green. 200>ppm Does this sound right?

Should i lower gH for the CRS?

Im topping up with saltyshrimp, should i be topping up with ro only to lower the gH?

Is something in the tank causing gH to go up?

The rest of my WP - pH <6.5, TDS 100ppm

[BlueBolts]

API test kit ? Each drop s 17.9 ppm.

Both KH & GH are high. Perfect for cherry/tiger but not CRS. Suprised that TDS is only 100ppm.....you 100% sure GH is correct ? If you're using RO water and salty shrimp only, then definitely something in the tank is raising KH and GH.

[Magikarp]

Are you only topping up? I was told that the evaporated water leaves the minerals in the tank. Maybe every time you top up you are adding more and more minerals to the tank. My LFS told me to top up with rain/RO only and WC with re/mineralised water. Someone please correct me if I'm wrong.

[BlueBolts]

Are you only topping up? I was told that the evaporated water leaves the minerals in the tank. Maybe every time you top up you are adding more and more minerals to the tank. My LFS told me to top up with rain/RO only and WC with re/mineralised water. Someone please correct me if I'm wrong.

Yep, that's right....

al4n only has a TDS of 100, so there appears to be something out of sequence with the WP...I think ?

[al4n]

Well I did a test this morning and kH was 3 and gH was 12.

I thought there might be something wrong but not a expert enough to confirm.

Should I do a WC with RO now to try drop the parameters? or is that going to cause deaths?

Should I take out the Benibachi mineral balls to help?

[Magikarp]

I've done a bit of reading to try to understand the relationship of GH and TDS for myself. Now what I've read is that GH tests for the amount of Calcium and Magnesium in the water and with your results (12*17.9=215ppm). Shouldn't the TDS be a minimum of 215ppm? as these are only 2 minerals that are in the water and the TDS meter would measure all minerals in the water.

Could it have been a false reading? My TDS meter(eBay) needs to be shaken/stirred whilst in the water to get a proper reading.

Can you try a different TDS meter?

[mr_c265]

Magikarp is completely right, sort of. PPM is a measure of parts per million of something in the total water volume. To have a GH of 215ppm means that something in the water has to be dissolved to the equivalent of 215ppm of CaCO3, however, it doesn't have to be 215ppm of CaCO3, it can be 3/4 of that weight in CaOH2 or 1.5 times that in Calcium Pyrophosphate, which will yield the same equivalent amount of Ca ions but add a different amount to the TDS. Same goes for Magnesium. However, unless you are in the habit of treating your tank with street de-icer or have some really funky minerals in there, it is highly unlikely that you actually have that much Calcium in the tank. Are you flipping the test tube after each drop to mix it in properly? How accurate is your TDS meter. Is your TDS meter in microsiemens or ppm?

[al4n]

The TDS meter I have is the blue generic one off eBay, I have another one which I'll try with tonight. From memory the results are in ppm.

I did exactly what the instructions says to do. I tip the bottle with cap every drip.

[mr_c265]

Even then it may be wrong, there are dozens of reasons that it may cause a false reading. Something doesn't seem right, thats all.

[al4n]

Alright, to make sure I did another test on the tank - same results. So i proceeded with below

I also test the water in my prepared water in container for top ups/WC and the results were - kH 1 and gH 4. TDS here was 101ppm

This tells me something in the tank is causing it? I have taken out the Mineral Balls as a precaution, and have done 10% WC. Opened my canister filter to check to see if anything in the media could cause but to no avail.

Although i am still stumped on why the TDS reading in the tank is 105ppm? and gH reading is 10+ >.

[al4n]

Its only getting better for me, I just tested TDS and its now showing 790ppm? wtf?

[Magikarp]

Test gh. If you still getting 12-13 I think it's a faulty tds pen.

Did you try your other one?

[al4n]

Update;

I have been doing WC with pure RO, and I have gotten gH 6 and kH 2 now. But my TDS reading on either of my pens are saying 550ppm. How do i lower TDS with touching gH/kH since they are okay now?

[Heavyd]

Maybe keep doing water changes with RO mixed with Salty shrimp, should keep your gH constant and remove the other dissolved solids from the water.

[al4n]

will do..

[Guest ANTHONYRAE]

Hi Mister.I just noticed this thread and I don't know what substrate or other materials are in your tank. But TDS isn't like a conductivity measure,which reads dissolved salts like Sodium etc.TDS includes dissolved organic material like urine,tannins and I imagine also any gasses like methane,CO2 etc without isolating any particular pollutant.Since the reading climbs with time,I'm guessing you have tannins and even uneaten food etc.SO,providing there is no prob in the nitrate direction,it's most likely fine.Purigen would probably bring the reading down in an hour or so.If the inmates are happy,I tend not to tamper.

Also,it's a big jump from RO to normal tank water,regardless of Mg and Ca levels,so a climb should be expected.

[al4n]

Thank you for your detailed post! I understand it much more.

Thanks again for everyone's input..