Can't Get My Alk Up

[Scottiemac]

I'm running Kalk plus a Calcium reactor. Yet my Alk has been stuck between 8.5 and 9 for a couple of weeks, and that's with the help of some AFR boosts when it gets below 8.5. Typically it runs from 9.5 to 10. Nothing has been added that would increase alkalinity consumption.

Yesterday I slowed down the CO2 and managed to keep the pH in the reactor at between 6.54 and 6.52, Prior to this it would fluctuate between 6.5 (off) and 6.7 (on), so I know the CO2 is still good. The media doesn't look much lower than when I added it last year.

Any suggestions as to why I can't keep my alkalinity up anymore?

 

[Randy Holmes-Farley]

Your current alk is perfectly fine, but as corals grow, demand will rise and perhaps the old settings just are not keeping up.

Can you raise the flow through the CaCO3/CO2 reactor, while maintainng the current pH?

 

[Scottiemac]

Your current alk is perfectly fine, but as corals grow, demand will rise and perhaps the old settings just are not keeping up.

Can you raise the flow through the CaCO3/CO2 reactor, while maintainng the current pH?

You mean increase the flow from the tank to the reactor and back to the tank, or the pump that runs water from the top of the pump to the bottom of it?

I can increase the flow from the tank, but wouldn't that reduce the strength of the effluent? Or am I misunderstanding? I thought that the longer the water was in the reactor, the stronger the effluent.

 

[Randy Holmes-Farley]

Flow from the tank. If you keep the pH the same (means adding more CO2), then you get more flow at the same potency.

 

[Scottiemac]

Flow from the tank. If you keep the pH the same (means adding more CO2), then you get more flow at the same potency.

Got it. Thanks - I'll give it a try and report back in a couple of days.

 

[Randy Holmes-Farley]

You're welcome.

Good luck!

 

[Scottiemac]

Flow from the tank. If you keep the pH the same (means adding more CO2), then you get more flow at the same potency.

I think half of it is resolved. My kalk reactor was gunked up, which is weird because it's relatively new. A little bit was getting through, but not enough. Eventually it closed up completely.

Anyway, after cleaning it my pH shot up to around 8.30, at which point it shut off as programmed. My alkalinity jumped from 8.7 to 9.7, which is closer to where I used to see it.

Now the pH is back down to around 7.9 and won't creep back up. I may have put too little kalk in the reactor, trying to prevent gunking.

But the alkalinity has remained stable through two tests.

 

[Randy Holmes-Farley]

Thanks for the update. :)