High alk

bensoo00 · Nov 23, 2023

I used the salifert test for Alkalinity/carbonate hardness and I ended up using all .8 ml of the solution in order to get a reading, meaning that I have a 15.7 kh value? I feel like this is insanely high and I am unsure of how to lower it. Any help would be good, thank you! I do not use RODI water if that is of any help. I also have about 6-10 sps corals and 2 lps in my tank, but only now have they started to suffer from this supposed fluctuation, as before, the lps were doing perfectly fine and branching out. I also double checked with the API Reef Master test kit for KH and the readings I got were 12 dKH and 214.8 ppm KH.

Nitrate 10 ppm
Nitrite 0 ppm
Chlorine 0 ppm
Ph > 8.4
Phosphate - between 0 and 0.25

ppm KH 214.8
KH 15.7
dKh 12

Jekyl · Nov 24, 2023

My gut says that your test reading wasn't right. I would get a second opinion. Also make sure to double check instructions and make sure you're reading the salifert test correctly. The syrette you have should be a 1.0ml so saying "used all .08" doesn't seem right to me

Mr. Mojo Rising · Nov 24, 2023

What kind of water do you use if not rodi? Your corals suffering might be due to the water source and quality.....

bensoo00 · Nov 24, 2023

I just use tap water, and PA tap water is pretty hard if that is of any help.

Jekyl · Nov 24, 2023

bensoo00 said:
I just use tap water, and PA tap water is pretty hard if that is of any help.

Problem with tap water is you really have no idea what's going in your tank. Fluoride, copper, pesticides, lead, you just don't know.
As mentioned before getting a second opinion on your result is a good idea. If you do want to keep coral, an RoDi system is necessary though.

Randy Holmes-Farley · Nov 24, 2023

Tap water can have more alk than the salt mix itself.

EeyoreIsMySpiritAnimal · Nov 24, 2023

bensoo00 said:
I used the salifert test for Alkalinity/carbonate hardness and I ended up using all .8 ml of the solution in order to get a reading, meaning that I have a 15.7 kh value? I feel like this is insanely high and I am unsure of how to lower it. Any help would be good, thank you! I do not use RODI water if that is of any help. I also have about 6-10 sps corals and 2 lps in my tank, but only now have they started to suffer from this supposed fluctuation, as before, the lps were doing perfectly fine and branching out. I also double checked with the API Reef Master test kit for KH and the readings I got were 12 dKH and 214.8 ppm KH.

Nitrate 10 ppm
Nitrite 0 ppm
Chlorine 0 ppm
Ph > 8.4
Phosphate - between 0 and 0.25

ppm KH 214.8
KH 15.7
dKh 12

As others have said, using RODI water is best. The next best would be distilled water from the grocery store. If you have an LFS nearby, go buy a few gallons of their RODI water and mix with your salt - then measure the alk. (If no LFS, try doing the same but with distilled water).

I noticed you tested for chlorine (good idea if you're using tap water); what type of dechlorinator did you use?

I'm not positive about whether you can use a saltwater alkalinity test for freshwater, but Randy will know... If you can, then definitely test your tap water too.
@Randy Holmes-Farley

EeyoreIsMySpiritAnimal · Nov 24, 2023

Also, what is the salinity of the water you tested?

EeyoreIsMySpiritAnimal · Nov 24, 2023

Jekyl said:
The syrette you have should be a 1.0ml so saying "used all .08" doesn't seem right to me

So many people don't read the directions, and so don't understand that the air in the syringe is from the tip, and that once you've drawn in liquid up to the 1ml mark, the total amount (the body of the syringe plus the tip) is a full 1ml.

bensoo00 · Nov 24, 2023

1.025

bensoo00 · Nov 24, 2023

Oh so in this case my reading should have been 0.2 ml instead of 0?

EeyoreIsMySpiritAnimal said:
So many people don't read the directions, and so don't understand that the air in the syringe is from the tip, and that once you've drawn in liquid up to the 1ml mark, the total amount (the body of the syringe plus the tip) is a full 1ml.

EeyoreIsMySpiritAnimal · Nov 24, 2023

bensoo00 said:
Oh so in this case my reading should have been 0.2 ml instead of 0?

Did you draw up the reagent until the bottom of the plunger sat at 1.0? If you did, then wherever the plunger was when the test was done (the color changed), that's the amount you subtract from 1.0.

bensoo00 · Nov 24, 2023

I did and I ended up using all the reagent and the plunger was at 0.2. So my reading was 0.8 then instead of 0?

EeyoreIsMySpiritAnimal said:
Did you draw up the reagent until the bottom of the plunger sat at 1.0? If you did, then wherever the plunger was when the test was done (the color changed), that's the amount you subtract from 1.0.

bensoo00 · Nov 24, 2023

I also use seachem prime as a dechlorinator

fishyjoes · Nov 24, 2023

Measure the alk in your tap water (or find a water quality report from your water supply company), then add that value to the published alk from your salt mix. If that comes up to around 15 dKh, then your test result was probably not false.

If the bottom of the plunger was at the 0.2 mark when you got the color change, that means your alk is 12.5, which roughly corresponds to what the API test gave you.

I also have the API alk test, and they only give you whole dKh readings, but they're easy and trustworthy, just not very precise (no small increments like salifert and others) - so I would say your alk is 12.5 and you just need to familiarize yourself with the salifert instructions.