flow and ph

[MPISCIOTTI]

2 weeks ago i upgraded my sump and added 2 genx pcx 30 pumps as my return. currentley i am only running one because of my sand bed 2 is to much flow..


but i have noticed the ph in my tank got really hi around 8.8 i have done nothing diffrent still dosed my kalk my ca reactor is still set the same..

so the last 2 days i have stopped using kalk and my ph is completey stable. could the new pump have made my ph more stable. so i do not have to top off with kalk anymore..

my concern is that on wensday im leaving for california to go snowboarding for a week.. im not sure what to use as top off while im gone. just plain rodi.. of rodi with kalk mixed into it..


also im going to be heading to marine depot. if anyone wants anything let me know...

 

[ShaunW]

A pump alone isn't able to stablize your pH, nor will it add Ca and Alk to your system, so I would consider still topping off with Kalk if it has been working for you.

One possible explaination for your observation is by increasing the flow your having greater gas exchange between the tank and surround air where CO2 locked up in your water before from organic respiration (without all the flow to remove it) is now able to escape your system.

I would let the pH come down (it is high probably because you have been overdosing with kalk and the CO2 present in the system previously cancelled out the pH somewhat, so that your pH looked normal). Then resume dosing with kalk.

Oh, BTW there are other explainations, I am just present one.

 

[MPISCIOTTI]

for the last 2 days the ph has not moved pass 8.2 so i think it is stable. i know when i do not drip kalk my system ph usally drops between 7.7 and a hi of 8.0....

 

[kimoyo]

whats your alk at?

 

[MPISCIOTTI]

the same it always is 12.5 salfiert test kit

 

[kimoyo]

Your alk should have dropped if you stopped dosing kalk. At 12.5 or (4.46 meq/l) with normal CO2 in your tank your ph should around 8.45. The more CO2 the lower the pH will go. So as Solbby said, getting the more water movement in the tank probably help to get rid of excessive CO2.



Here is a very good article on the subject, http://www.reefkeeping.com/issues/2004-09/rhf/index.php.

 

[MPISCIOTTI]

the ph at the moment is 8.3 when the lights were off i checked it at 4 am it was 8.2