PH 8.6, What range for dKH ?

[fnscasey]

My PH level when i measure this afternoon is 8.6. Is that considered high ? At that level of PH, what is my range of dKH ?

Is it true that if dKH is between 8-10dKH, than PH level is stable at 8.0-8.4 ?

[Fishboy-from-NY]

I would be a water change dude, your PH is pretty high, if you have a fish only tank, you can keep your PH at around 8.0-8.2. As for DKH, 8-10 should be ok.

[biotoxin]

a water change really wont help with a PH issue. What you need to do is test during the end of a lighting cycle and also make sure you have sufficient surface aggitation. You need 10x the flow per hour in your tank to keep the c02 and gaseous exchange happening. Also dont cover the top of your tank with glass. Take out some water from the tank, let it set out a few hours or over night then retest. If there's a significant difference then you know your flow is too low/high.

[packfan2204]

so u can have too high a flow in ur tank, because i've done a lot of water changes in the past two weeks, and still can't get my pH down. And i knew when ur pH is low, u don't have enough flow, and i was wondering if the opposite is true, if u have too much flow, ur pH will go too high. Cause i can't for the life of me figure out how to get my pH down.

Originally Posted by packfan2204

so u can have too high a flow in ur tank, because i've done a lot of water changes in the past two weeks, and still can't get my pH down. And i knew when ur pH is low, u don't have enough flow, and i was wondering if the opposite is true, if u have too much flow, ur pH will go too high. Cause i can't for the life of me figure out how to get my pH down.

Actually there is only so much O2 the water will hold so once that point is reached, no amount of water flow will increase the gas exchange and allow such an increase in the ph without some sort of chemical addition. The constant water changes however will spike the ph somewhat. Stop doing them for the time being and allow the chemistry to settle on it's own. Test the ph tomorrow in the AM, at midday and later in the evening to see what you get. Also note that testing the ph within several hours of buffer additions or water changes will greatly affect your readings (higher). The sample water that is removed from the tank must also be tested within minutes of removing from the tank. Any amount of ambient O2/CO2 will affect the reading as well so do not dally with the test.

Check your source water (RO?) to see what the reading is there. Might be an issue with the test being accurate.

Cheers
Steve