I'll have some soon (in route), I'm not sure whether Greg Watson will sell the 10ml NIST reference samples or not.

But given the KNO3, KH2PO4 and ferts that are sold through his company, CO2 is an obvious crux for the entire fertilization routine.

A simple drop checker with a lab grade reference sample that makes 3.5 liter's worth of highly accurate KH is a nice item, easy to ship and available.

I'll have several 10ml samples, so if you want, you can have some of the 4KH stuff.
Say a liter or so. I can send it in about a week.

Then you can use that and determine any of the issues and do away entirely with a KH Test kit.

Which for 10$, the KH reference solution should seem mighty simple and cheap vs taking a test measurement etc and paying for that for say 50 test. How many Drop checker test would you get for 10$ and 3.5 liters if the volume is 5mls in the drop checker?

700 test and that assumes they are only measured once, drop checker refills last quite some time.

So it's certainly cheaper than KH test kits and gets away from testing.

The only thing I want to test is pH and very accurately determine CO2. The nutrients can easily be addressed with EI.

And I have that goal within my reach now.
No KH test kits anymore for me.

Only pH.

Like E=mc^2, a good method focuses very critically to get elegant simplication.

EI+ADA AS(you can chose others obviously, but this one works well and cost the same as many of others) + KH ref solution appears to achieve this.

Dail in the correct CO2, do the routine water changes and dosing, garden, clean etc. Testing is avoided other than pH meter or color changes in a drop checker.

Now that's powerful and radically changes the way folks do the hobby and makes it a lot more stable, consistent and simple. Tap water variations are not an issue.
Does the tap water add CO2 after a water change? How much? Now you can tell with the ref KH solution easily.

It's also cheaper/more standard than any other method for KH and dosing of ferts.
I can measure KH, CO2, pH, all the nutrients, O2 production to a much higher degree of rigor and with less work for less $. If any critics have a better method, I'm all ears.


Regards,
Tom Barr

I wish we had a UK supplier as forward thinking as Greg Watson. If it works out, maybe its worth me contacting Aquatic Essentials (uk) and suggesting they run something similar in their product line. Theyd clean up.

Tell him to contact me and he can sell the lab certified KH reference solutions also.

Regards,
Tom Barr

Hi, just want to confirm my calculations to make a 5°Kh solution starting with a 40°Kh reference solution, i would add 100ml of the 40° solution to 700ml of distilled water to make 800ml of 5°Kh solution. is this correct?

That looks correct to me, but don't forget that making the 40 dKH reference solution requires other than 4.99 gm of sodium bicarbonate in 5 liters of water. See the posts on the second page.

Ive emailed Aquatic Essentials (UK) Tom and suggested that they get in touch with you regarding stocking this item. It would be great if they would, for alot of us.

There are now KH Standards available here on the "Trades, swap, sales" forum and on Aqua Bid under test kits.

Bill

There you all go.

Regards,
Tom Barr

I skimmed through this thread, so pardon me if it's already been answered. But why use Baking Soda over Calcium Carbonate? Will the moisture content of my CACO3 be an issue as well?

I'll probably just buy a sample in any event, but I was curious.

Try dissolving Baking soda vs CaCO3.

Regards,
Tom Barr