Help with kh/ph

[wasabi bean]

So a couple of weeks back i found my kh was like 5.5 which i know is really low as i thought ph was the same (i know dumb) now i am dosing sodium bicarbonate as my calcium is fine. The only issue with this is now my alk is stable at 6 but my ph is already at 8.4 compared to the 8.1 i started with. Using that maths my ph would be crazy high to get my alk to a healthy value. What should i do, if i did frequent WC’s to get it up would it then again be stable with how much i am dosing or will it Just drop very quickly.

 

[lombeard]

can you tell us more about your tank? are you dosing daily or did you dose it to 6 and stop? what is a healthy KH value to you?

i've run my tanks between 6 and 7 for the longest time and corals are just fine.

 

[wasabi bean]

Oh yeah sorry, it is a 255 litre tank whole system is probably 280 litres with displacement, i am dosing on the hour every day with 1.5ml of concentrated sodium bicarbonate as my pump can only be programmed for 24 times a day, i am still dosing this amount just to stay at 6, ideally i would like kh to be above 7 and at 8 if possible

 

[lombeard]

You could manually dose a little extra over a few days and increase the KH to that number, increasing by 0.5 per day (I've done +1 many times with no issues) but it never hurts to go slower.

 

[Randy Holmes-Farley]

pH will never get too high due to dosing sodium bicarbonate to maintain normal alk levels.

 

[wasabi bean]

pH will never get too high due to dosing sodium bicarbonate to maintain normal alk levels.

So does that mean the ph increase levels off eventually or do you think it is just a miss test?

 

[Randy Holmes-Farley]

So does that mean the ph increase levels off eventually or do you think it is just a miss test?

Bicarbonate addition itself does not boost pH, though higher alk allows a higher pH at equilibrium with air.

 

[wasabi bean]

Thanks all, i just used a physical test kit rather than my probe and it said it was actually around 8.1 where it was before dosing, guess i need to recalibrate my probe and actually test rather than relying on it

 

[timqmana]

Thanks all, i just used a physical test kit rather than my probe and it said it was actually around 8.1 where it was before dosing, guess i need to recalibrate my probe and actually test rather than relying on it

Did you test your pH at the same time of day? PH fluctuates throughout the day.

Either way, you shouldn't have to worry about your pH with what you've told us so far.

 

[wasabi bean]

Did you test your pH at the same time of day? PH fluctuates throughout the day.

Either way, you shouldn't have to worry about your pH with what you've told us so far.

I mean my ph probe gives data every minute so it said at that time it was 8.4 so i am going to up the sodium bicarbonate dosing as i know now that ph isn’t a problem, thanks all