Alkalinity

[Sajacobs]

Hello everyone,

I hope I'm in the right place for this! My alkalinity keeps going up, ph and calcium are staying level but the alkalinity is now at 12 dkh

Salnity 35
Ph 7.94
Calcium 493
Magnesium 1400
Ammonia 0
No2 0
No3 5
Phosphate 0.05

I am not dosing doing water changes 20% once a week (salt is aquaforest reef salt) before water change 12.4dkh then after 11.2 dkh rising .2dkh (testing daily alkalinity and calcium till I get this sorted) then 11.5 to 12 yesterday to today. Am I missing something?

 

[PBar]

Hi,
if you are not dosing nothing and doing 20% TPA weekly, I can only assume that the alkalinity of your tank is matching the same as your new water.
As such, the deviation could be probably related to test error margin.

Which test are you using?
What is the alkalinity of your new water? That could solve if there is a error from your hobby test.
Seems that the alkalinity from your salt should be be 7.5 and 8.3 depending on the salinity...

 

[bsr2430]

Agreed with above!
Your test kit could be off. Do you have a second laying around?

Also, I see you’re new here! Welcome!
Another one sucked in...

 

[Sajacobs]

Thank you for you welcome and advice I am using hanna checker. I have red sea I will get my son to test with that after he has done another water change! I use my own rodi water to make my saltwater. We checked the water we have already mixed it is at 34 salinity but the alkalinity came up at 6.9 dkh. I am wondering if i have a bad batch of salt? Is that possible?

 

[bsr2430]

Thank you for you welcome and advice I am using hanna checker. I have red sea I will get my son to test with that after he has done another water change! I use my own rodi water to make my saltwater. We checked the water we have already mixed it is at 34 salinity but the alkalinity came up at 6.9 dkh. I am wondering if i have a bad batch of salt? Is that possible?

Before a bad batch of salt, 99.99% of the time it will be the checker. Never actually heard of a bad batch of salt.

Another theory to bust, can you use a different salt? That would tell you what’s happening. I use reef crystals and I’m use you could pick up a small box from your local pet store.

If you’re not dosing as you say you’re not and only doing salt water changes by 20%, it can’t be any other thing besides the checker being bad.

Yes you’re most likely topping off the Alk in here but it should come down when doing so, not really matching what already exists. Mathematically this doesn’t add up in my head.

 

[Randy Holmes-Farley Verified Community Expert]

Alkalinity rises if nitrate is falling by consumption.

0.2 dKH boost to alk comes from a drop of nitrate by about 4.3 ppm.

 

[Sajacobs]

Before a bad batch of salt, 99.99% of the time it will be the checker. Never actually heard of a bad batch of salt.

Another theory to bust, can you use a different salt? That would tell you what’s happening. I use reef crystals and I’m use you could pick up a small box from your local pet store.

If you’re not dosing as you say you’re not and only doing salt water changes by 20%, it can’t be any other thing besides the checker being bad.

Yes you’re most likely topping off the Alk in here but it should come down when doing so, not really matching what already exists. Mathematically this doesn’t add up in my head.

Looking back at the numbers I have the alk was around 2.5 to 3 meq/l before I got the checker? Do you think I should contact hanna?

 

[Sajacobs]

Alkalinity rises if nitrate is falling by consumption.

0.2 dKH boost to alk comes from a drop of nitrate by about 4.3 ppm.

Nitrate has only changed 7ppm to 5ppm in the last 6 weeks numbers have been level in ammonia and no2 and no3. Have I missed something? In my other tanks I don't test alkalinity so this is new to me

 

[rimlessreefer954]

how old is your tank? how big is your tank? and how many corals do you have?

 

[Randy Holmes-Farley Verified Community Expert]

There are other reason alkalinity rises, such as the slow dissolving of calcium carbonate sand.
Do you use tap water?

What do you read as the alkalinity in the new salt water?

 

[Sajacobs]

how old is your tank? how big is your tank? and how many corals do you have?

Tank is 5 months old, 32 gallons, some zoas and 6 lps.
Does this matter?

 

[Sajacobs]

There are other reason alkalinity rises, such as the slow dissolving of calcium carbonate sand.
Do you use tap water?

What do you read as the alkalinity in the new salt water?

The sand was live sand from my lfs I can't remember the type, I have my own rodi unit, the tds on that is 0! The tap water here is not great for the shrimp, planted tank and pea puffers!
We tested the batch we have ready and its 6.9 dkh at 34 salinity.

 

[Sajacobs]

Before a bad batch of salt, 99.99% of the time it will be the checker. Never actually heard of a bad batch of salt.

Another theory to bust, can you use a different salt? That would tell you what’s happening. I use reef crystals and I’m use you could pick up a small box from your local pet store.

If you’re not dosing as you say you’re not and only doing salt water changes by 20%, it can’t be any other thing besides the checker being bad.

Yes you’re most likely topping off the Alk in here but it should come down when doing so, not really matching what already exists. Mathematically this doesn’t add up in my head.

I have bought new salt and we are going to swap it over, how slowly should you do this inread that you need to do 75/25 the 50/50 then 25/75 is this what you recommend?

 

[Randy Holmes-Farley Verified Community Expert]

I have bought new salt and we are going to swap it over, how slowly should you do this inread that you need to do 75/25 the 50/50 then 25/75 is this what you recommend?

Just use whatever is your normal water change protocol.