Low alk, need to balance before dialing in cax

[DonW]

I know what you mean. I'll watch it. If the flow stops, I don't see any real problems since I'm using a ph contoller that woudl shut off co2 if the ph got too low.

i'm just worried with an effluent rate of 50ml/m, i could overload the system too quickly. I really don't have a huge CA demand. Which again begs the question why i'm using a cax. Reason is, Kalk alone wasn't cutting it. But i didn't have to dose much calcium chloride either, so my CA load is lower.

You can run high effluent rates without overdosing your system. 50ml is not even close to high. Most people run into problems trying very low rates. Its much harder to control your alk although it uses less co2 its difficult to make adjustments especially for those that dont have the carx experience.

Don

 

[zenn]

so getting to 6.7 for an effluent ph isn't necessarily the goal? I should worry more about starting with a drip rate of 50ml/m....then start out with a really low bpm (like 10) and just increase bpm until my alk/ca stays stable in the display?

 

[DonW]

so getting to 6.7 for an effluent ph isn't necessarily the goal? I should worry more about starting with a drip rate of 50ml/m....then start out with a really low bpm (like 10) and just increase bpm until my alk/ca stays stable in the display?

Lets see if I can phrase this better, sorry I'm not a good teacher.
If your effluent rate is medium high like 100+ ml it takes more co2 to bring the ph down. So if you need to make a fine adjustment it may take 5 or 10bpm either direction just to make a small ph adjustment.
If you were to try 50 drops per minutes. Just a single bmp might make a big difference.

I would NOT concentrate on that 6.7 mark. If you check the alk on your effluent and its higher than your tank then you are adding alk even if the reactor ph is 7. and that alone may very well be plenty at this stage in the game.

Make sense.
Don

 

[zenn]

Lets see if I can phrase this better, sorry I'm not a good teacher.
If your effluent rate is medium high like 100+ ml it takes more co2 to bring the ph down. So if you need to make a fine adjustment it may take 5 or 10bpm either direction just to make a small ph adjustment.
If you were to try 50 drops per minutes. Just a single bmp might make a big difference.

I would NOT concentrate on that 6.7 mark. If you check the alk on your effluent and its higher than your tank then you are adding alk even if the reactor ph is 7. and that alone may very well be plenty at this stage in the game.

Make sense.
Don

yes, i think i've got a good plan now. I can't say thanks enough for posting back right away all day helping me out. I'm pretty sure I've confused myself about a million times already with this carx stuff. The more I read and talk about it though, the more sense it's making. So thanks for all the information; things are definitively making more sense after today.