Help...How to read KH test

[Mark3]

I don't understand the API KH carbonate hardness test kit....color change at 18 drops so, ... a KH of 327ppm by their chart

How does this KH reading translate into what I need to know?

Is that equivalent to Alkalinity ppm numbers? or how does it translate?

PS: Calcium test is at 18 or 19 drops 360/380 ....I understand this one. and PH at 8.3

 

[Spare time]

Their test should be 1 drop = 1 KH. API Alkalinity its not read in ppm like their calcium but rather in KH. If it isn't changing colors till 18 drops then either something is wrong with the test, user error, or you somehow overdosed alk into the tank. When it changes colors, the amount of drops you had put in what your alkalinity is at.

 

[JimWelsh]

Alkalinity is sometimes expressed as PPM of CaCO3. 327 PPM of alkalinity as CaCO3 equals 6.54 meq/L equals 18.3 dKH. Like @Spare time said, either there is a problem with the test kit, or you are doing something wrong, or you have around 18 dKH of alkalinity. Get another test kit (I like Salifert) and double-check your results.

 

[jordan10]

That means 18 dkh real high target should be 7 to 9 other people have it on high side I keep mine round 7.5

 

[Mark3]

Hummm.....OK I already double checked the result = 18 drops and checked the expiration of the test kit. Checked again today... yes, 18 drops on the third time testing

Today is Saturday,...my agenda is get a new test kit and test before and after a 20 gallon water change with both testing kits and compare results.........out of curiosity, I am going to take a sample to Marine Warehouse to see what they test it at...want to rule out user error.

will update you all on this.....thanks for your replies

 

[Mark3]

Update....
just got back from Marine Warehouse, Tampa and guess what....
...they came up with the exact same as me....18 drops, ...she dumped it the first time and started over, thought she was wrong.

No user error, and no test failure, so I didn't buy a new test kit, ...going to do a 20 gallon water change and test again.

 

[Randy Holmes-Farley]

Do you use tap water? What salt mix? Some tap water with a higher alk salt mix will give alk like you have.

 

[Mark3]

No, I usE RO/DI water with 0 TDS and use Instant Ocean Reef Crystals, orange box.
.
I just finished a 20 gallon water change and making more water for another 20 gallon change tomorrow.

40 gallon change should make a good difference ...125g tank with 40g sump ...about 150 g total volume.

I did a quick KH test....better already....15 drops and it has only been about half an hour for new water to mix into tank water.... tomorrow will do another water change and a round of testing.

What I am wondering about is how can ALK be so high, and yet everything else seems to be pretty normal. ...maybe it's that bag of Cheetos I put in the sump? ... (never know who to listen to)

 

[Randy Holmes-Farley]

Alk cannot generally rise on its own, but many products boost alk, even some where you wouldn’t know it from the manufacturer description. What all have you added to the tank or new water?

 

[Mark3]

Alkalinity is sometimes expressed as PPM of CaCO3. 327 PPM of alkalinity as CaCO3 equals 6.54 meq/L equals 18.3 dKH. Like @Spare time said, either there is a problem with the test kit, or you are doing something wrong, or you have around 18 dKH of alkalinity. Get another test kit (I like Salifert) and double-check your results.

Thank you, this is the info I was looking for. The answer is: I DO HAVE around 18 dKH of alkalinity. I wasn't sure of how the numbers correspond to each other.

PS LFS said they didn't carry Salifert, can't compete with online pricing.

 

[Randy Holmes-Farley]

Thank you, this is the info I was looking for. The answer is: I DO HAVE around 18 dKH of alkalinity. I wasn't sure of how the numbers correspond to each other.

yes. The question is why.

 

[Mark3]

Alk cannot generally rise on its own, but many products boost alk, even some where you wouldn’t know it from the manufacturer description. What all have you added to the tank or new water?

Pretty sure I know what I have done....I add Seachem Reef Buffer to the top off water to raise PH....after time overdose, totally my fault, I think I should of been adding kalkwasser instead?
Need to go to reef school. AND test what you add ... I was only testing the PH with the buffer and not the alk

 

[Randy Holmes-Farley]

Pretty sure I know what I have done....I add Seachem Reef Buffer to the top off water to raise PH....after time overdose, totally my fault, I think I should of been adding kalkwasser instead?
Need to go to reef school. AND test what you add ... I was only testing the PH with the buffer and not the alk

That would do it. Don't add anything to top off water unless you are using it as a way to add alkalinity.

I know it may not seem logical, but adding pure fresh water with a pH of 7 actually raises the pH of seawater with a pH of 8.2. Pure RO/DI water (TDS = 0 ppm) is never, ever the cause of low pH in a reef tank, no matter what pH you think it is (which also cannot be measured correctly by hobby equipment or test kits).

 

[Dkeller_nc]

Yep, that explains it. In seawater, you can't add any chemicals to the water that will raise pH without increasing the alkalinity.

 

[Mark3]

What about adding Kalkwasser to the top off water .... wouldn't that be the same as dosing it? I realize I was not testing correctly, but I learned my lesson there, and will test every time I add something. I really want to bring the quality of my tank up. It has just been coasting for many years and I want to put some effort into having it grow some nice color. Right now it is overrun with Kenya Trees (Kenya Forest). They just don't have any color.

What has nice bright color, but is very easy to grow....I don't mind pruning, I pluck Kenya Trees out often...would love them if they had good color to them.

Anyway...my question is how best to increase the quality of water...is dosing in the top off water a bad idea? My top off is pretty consistent at 5 gallons a day. I don't have ATO, I fill it by hand EVERY DAY !

 

[Randy Holmes-Farley]

Dosing limewater in top off is a fine idea. I did it for 20 years. But only do it if you need alkalinity. If you need no alkalinity, alk will rise. It also needs to be added slowly

 

[Mark3]

Which way do you think the leather coral in the center is more happy...stretching out or pulled in....photos 2 days apart.

I'm not sure? is it ticked off now, or is it more relaxed now? was it reaching for life before... tucked in since yesterday's water change

 

[Randy Holmes-Farley]

Top is happy. Closed is less so, but they can be irritated by many things.