Salty shrimp GH/KH+

[sarah]

I've been having molting issues in my tank, so I decided to test all the parameters in my remineralized water instead of just mixing up to a 200 TDS. I use SS GH/KH+ and the website description says:

 

Use to re-mineralise RO water, rainwater, fully desalinated water etc. to reach a total hardness of about 6 °dGH and/or a conductance of about 300 +/- 50 µS (Microsiemens).

 

My bucket of remineralized DI water has the following parameters:

 

TDS 196

KH 3

GH 8

pH 8 - 8.2

 

This makes no sense at all. What the heck is going on here??

Any ideas?

[sarah]

Nevermind! The company wrote back immediately, and I can't believe I was using TDS instead of µS!

 

Going to dilute my batch now and test params again....

[zodiac]

you know,after many uses of the pen the tds will show a higher tds then what it really is.

with SS GH/KH+,200 tds is not 8 gh.

tds is closer to 150.

you need to test the water you mix once in a while and adjust your tds number or calibrate the pen.

you should also test the gh of your tank once in a while.

[sarah]

Thanks. I will definitely check my TDS pen. I actually have another one laying around somewhere, so I will compare readings.

 

When I diluted my bucket of water to TDS 150, GH was 6 and KH was 2-3.

What's weird is my pH stayed at 8. This seems really high, doesn't it?

[zodiac]

maybe you need to calibrate your ph pen. 

i don't test ph,but it does sound high with that little kh.

[sarah]

Just checked - both TDS meters had same result.

 

The company responded that the powder will have no effect on pH. Only the acids in my tank have an effect on pH.

 

I just made up a new batch of TDS 175 water using even purer water (nanopure lab-grade 18.2MΩ-cm) and the pH is even higher.

I verified my API liquid pH test results using a lab-grade pH meter. Tank water is at 7.81 and new water that I just mixed is at 8.71!

 

Now I'm really baffled.

[Shrimple minded]

"One of the most common issues that reefkeepers face involves supplementing alkalinity while maintaining a reasonable pH. Alkalinity supplements impact pH in a variety of ways. One of these ways is the immediate altering of the pH."

 

http://www.advancedaquarist.com/2002/5/chemistry_album/figure1.gif/image_preview

 

http://www.advancedaquarist.com/2002/5/chemistry

[sarah]

"One of the most common issues that reefkeepers face involves supplementing alkalinity while maintaining a reasonable pH. Alkalinity supplements impact pH in a variety of ways. One of these ways is the immediate altering of the pH."

 

http://www.advancedaquarist.com/2002/5/chemistry_album/figure1.gif/image_preview

 

http://www.advancedaquarist.com/2002/5/chemistry

 

Interesting. I really don't know what to do at this point. My tank pH is too high as it is, so I don't think I should do a water change today with this crazy high-pH water.

Maybe I just need to switch remineralizers entirely.

 

Any advice?

[Shrimple minded]

I'm curious to what your remineralized RO pH does after 24-48-72 hours.  It has been documented that there are many challenges accurately measuring pH in low-TDS, softwater scenarios (freshwater shrimpkeeping using RO).  

 

Without being sure that pH is what is causing your molting issues, I wouldn't start fiddling with pH much, specifically since your tank pH of 7.81 is still within suitable neocaridina parameters.

 

I'm hoping that over time, your new water will drop pH to something below 8, and you can proceed as before.

[sarah]

I've been using this same SS GH/KH+ for almost a year, but I never though to test pH in the bucket. My pH in my tank has been slowly creeping up so I've started to worry. I wonder if I have been adding water with a higher pH all along, and my tank was bringing it down a bit.

 

I am going to wait and not change the water today. Will re-test the bucket tomorrow and see...

[sarah]

I stuck an airstone in there. Will retest tomorrow.

[Trotwood]

I have the same result when I use Gh/Kh+. The PH goes up to at least 8 when I mix the water to a TDS of about 150. It drops a bit when I let it sit but remains quite high. I decided not to worry about it and haven't had any problems in the 8 months or so I've been using it for neos and tigers.

[sarah]

I have the same result when I use Gh/Kh+. The PH goes up to at least 8 when I mix the water to a TDS of about 150. It drops a bit when I let it sit but remains quite high. I decided not to worry about it and haven't had any problems in the 8 months or so I've been using it for neos and tigers.

 

Wow, interesting. Glad it's not just me. What is the pH in your tank? Would you mind sharing your other parameters too?

[sarah]

Well, after less than 24 hours, the pH in the bucket is 7.65.

Water change time

 

Thank you all for your input!

[Shrimple minded]

Schweet!  Should settle to something reasonable in your tank.  

[Duff0712]

I have the same results when I test the Gh+/KH+ in the bucket. However, in my tank my PH would plummet and I still haven't found out why (I have bog logs, but nothing else to lower ph from 8ish in bucket to <6). 

 

I had very little life in my tank so over the past week I was adding the SS directly to my tank. I would add around 1/2 of the spoon daily unless I saw any signs of stress.

 

Before PH <6, TDS 180~ and KH 5-6.

After PH 7-7.2, TDS 250~ and KH 7-8.

 

I definitely don't recommend just dosing into the tank, but those are my findings.