alkalinity

[nemo79]

Hey everyone,

I have been having a hard time maintaining my alk and calcium. I have been supp with 2 part esv bionic. I tested tonight and my ca is 400 but my alk has dropped to 7 dkh!!!

I tested my mag last week and it was 1500(salifert test)

all else is good.

PH 8.4
ca 400
phos 0
nitrate 0

[coral reefer]

Have you tried using another test kit? Maybe you have a faulty kit...you may want to try to lower your pH as well and see if that helps to increase your alkalinity.
Another thing to do is slowly add alkalinity(buffer) to your tank slowly and don't add calcium and see if that helps!

[MDeth]

Also, is what time did you measure that pH? I believe tangster always says pH fluctuates during the course of the day.

[Otty]

If you are dosing a 2 part additive it says on there to do it in the morning so you don't have a big PH swing. When are you adding the dose?

[coral reefer]

Excess CO2 will tend to cause pH values to decrease, even despite adequate alkalinity levels. That is the ruling for adding Kalkwasser during the day as kalk has a pH value of somewhere around 12. If you dose kalkwasser at night, it is best to administer ACETIC ACID(VINEGAR) AS WELL TO HELP TO ENSURE THAT YOUR PH VALUE DOESN'T GO THROUGH THE ROOF.

[nemo79]

I add my additives in the morning before lights are on. I test my tank at night. my Ph is always 8.4 when I test at night. It was around 8:30pm when I tested. I don't use kalk...all liquid supplements.

[reef_guru]

balance for Ca and dKH :
Ca @ 400 dKH @ 4 or 1.5 meq/L
Ca @ 420 dKH @ 7 or 2.5 meq/L

a way to raise just your Ca is calcium chloride, some liquid supplements that raise Ca also have a buffer ( i.e. boron ) that keeps the dKH the same. if you follow the above balanced ratio and match your consumption rate of the tank, your levels wont swing as much.

Ph also comes from a high O2 level
dry media and liquid combination supplements are balanced

p.s.
my tank is automatically dosed every 7 hrs, 24 hrs a day with a minor Ph fluctuation

[Frizza]

Originally Posted by coral reefer

Excess CO2 will tend to cause pH values to decrease, even despite adequate alkalinity levels. That is the ruling for adding Kalkwasser during the day as kalk has a pH value of somewhere around 12. If you dose kalkwasser at night, it is best to administer ACETIC ACID(VINEGAR) AS WELL TO HELP TO ENSURE THAT YOUR PH VALUE DOESN'T GO THROUGH THE ROOF.

I agree with excess CO2, however I'm not sure if I've read your post correctly but I would recommend that you dose kalk at night time/early hours of the morning when the lights go out. A tanks ph will be higher during the day so adding kalk will increase this further! In addition to that, this is why some people use reverse photo periods to stabilise the ph after the main tank lights go out.