Help with Alkalinity increase

[miller75]

I need some help with my alkalinity.

I have posted a couple of times about my alkalinity increasing for an unknown reason, the only thing I can put it down to is my sand bed. I am currently adding Seachem Acid Buffer to my salt mix to drop the alkalinity to about 6dkh and then doing a 15% water change, this will drop it from 12 down to about 11.2 but it will be back up and rising within a few days I am currently sitting at 12.3 dkh

I really didnt want to dose the Acid Buffer directly into the tank but I am running out of options, can anyone see an issue with mixing 25g of buffer into 100ml of water and dosing over 3 days?

Its 2 g per 80 litres for a drop of 0.6 dkh, my water volume is 500l so that should give me a drop of 1.2dkh over the 3 days.

My plan is to get it back down to 8dkh and keep it stable until my consumption increases or the sand stops releasing it.

Just for info

I have tested with KH Director, Hanna and Salifert
I havent had any large nitrate drops
I am only dosing 8ml of nopox and nothing else
I have double checked my salinity

 

[Randy Holmes-Farley]

Direct tank dosing is ok but it lowers pH a lot so keep up aeration and go very slow.

I recommend a diy as opposed to the Seachem product.

Are you dosing anything else?

Is nitrate declining?

Do you use tap water?

 

[miller75]

Direct tank dosing is ok but it lowers pH a lot so keep up aeration and go very slow.

I recommend a diy as opposed to the Seachem product.

Are you dosing anything else?

Is nitrate declining?

Do you use tap water?

Hi Randy

I must admit its driving me mad trying to get to the bottom of this

I am not dosing anything else, nitrate is reducing slightly because of the nopox and I am using RODI water.

My salt mix is 8.2 before I reduce It, I tested my RODI with the Hanna and that came out at zero.

I am planning on dosing 1.3ml of the mix every hour during the day to give the PH chance to come back up, that should only drop it by about 0.016dkh per hour. If I dont have any PH issues I will increase that to every hour 24 times a day

 

[miller75]

Duplicate post

 

[Randy Holmes-Farley]

Nitrate consumption/reduction raises alk. 2.3 dKH per 50 ppm reduced.

Slow dissolution of rock and sand will happen in most tanks, and that effect just gets buried under normal alk and calcium demand, but in a low demand tank it can become bothersome.