Lowering DKH over time…

[WhatCouldGoWrong71]

I currently run a CARX whose feed pump shuts off from 11pm to 8am. I control the affluent by use of the PH probe and my Apex. Currently running a PH of 6.31 to 6.36 and my affluent DKH is 35. I’m running just shy of 100 ML/MIN. I run Kalk 24/7. But from 11 to 8 I drip 18,000 ML and then I drip 5k during the 8am to 11pm schedule.

My DKH is very stable 9.3-9.4. I want to start working it down to 8.0-8.3.

I thought about backing my feed pump down to 80 ML/MIN and changing my PH set points to 6.39-6.44. And putting a rule tied to my AquaWiz (tests hourly) that the feed pump shuts off above certain steps. Like start at 8.9. Then in 2 weeks raise the PH set points to 6.41-6.46. Rinse and repeat.

For those who use a CARX and Kalk, how would you go about doing this?

 

[Randy Holmes-Farley]

I would always raise the pH or reduce the flow. Having it shut off for part of a day risks it becoming stagnant inside the reactor when it turns off.,

 

[WhatCouldGoWrong71]

I would always raise the pH or reduce the flow. Having it shut off for part of a day risks it becoming stagnant inside the reactor when it turns off.,

I run the recirculation pump that keeps the water moving between the main chamber of my CARX and the saturation chamber. On a side note, you know that stench when you have tank water that sat and it really smells bad? Would an ORP gauge drop meaningfully if it were submerged in that water? I’m running 3 Apex brains to prevent issues that larger systems stumble across with an Apex. I have a spare ORP gauge and all 3 brains will accept an ORP probe. I have an idea.

 

[mcarroll]

For those who use a CARX and Kalk, how would you go about doing this?

Don't really need a reactor to answer this: Focus on changing one thing at a time. Assess the results of the change. Reformulate your plan as needed before taking the next step.

BTW, are you chasing a problem or why the changes? You described things as "nice and stable" yet about to upset the apple cart. :)

 

[WhatCouldGoWrong71]

Don't really need a reactor to answer this: Focus on changing one thing at a time. Assess the results of the change. Reformulate your plan as needed before taking the next step.

BTW, are you chasing a problem or why the changes? You described things as "nice and stable" yet about to upset the apple cart. :)

Running at 9.3-9.5 has its benefits. But it has its hinderances too. In an all SPS tank like mine (mostly) coral tend to be more brittle, or so I read. I still don’t need a coral saw as my fish do a heck of a job fragging my tank for me. Also, I’m at the max for my Kamoer fxstp. If I back it down, it will give me some more room with my Kamoer.

 

[mcarroll]

Running at 9.3-9.5 has its benefits. But it has its hinderances too. In an all SPS tank like mine (mostly) coral tend to be more brittle, or so I read. I still don’t need a coral saw as my fish do a heck of a job fragging my tank for me.

I'll be a cheerleading for keeping the status quo. (Even though I have no dog in the race and you should do what makes sense for your situation, not necessarily what we tell you.)

Unless you're *actually* seeing those hindrances you mentioned, consider them hearsay. Unless you see it *and* it is causing an actual problem, it's just nature being nature.

"Too brittle" is a human judgement....I'm not sure what our criteria is. Corals frag in nature as a way of life – of spreading their genes.

On the other hand, STN is generally related to a breakdown of photosynthesis due to one or more factors like too much light, not enough flow, not enough phosphates. These are some of the most common, but other factors figure in too, such as instability (eg alk, phoshpates).

Also, I’m at the max for my Kamoer fxstp. If I back it down, it will give me some more room with my Kamoer.

I always did DIY Randy's Recipe #2 and never managed to hit a limit on my doser. Maybe consider Recipe #2 and/or the plain-jane Jebao doser?

 

[Randy Holmes-Farley]

I run the recirculation pump that keeps the water moving between the main chamber of my CARX and the saturation chamber. On a side note, you know that stench when you have tank water that sat and it really smells bad? Would an ORP gauge drop meaningfully if it were submerged in that water? I’m running 3 Apex brains to prevent issues that larger systems stumble across with an Apex. I have a spare ORP gauge and all 3 brains will accept an ORP probe. I have an idea.

ORP is likely to drop, yes.

 

[Randy Holmes-Farley]

Running at 9.3-9.5 has its benefits. But it has its hinderances too. In an all SPS tank like mine (mostly) coral tend to be more brittle, or so I read. I still don’t need a coral saw as my fish do a heck of a job fragging my tank for me. Also, I’m at the max for my Kamoer fxstp. If I back it down, it will give me some more room with my Kamoer.

Folks repeat that claim, and it may be true, but I’ve never seen any primary information supporting it. I’m somewhat skeptical for that reason. Same applies to all other factors that get attributed to brittleness, though I can more readily believe flow impacts it than random chemicals such as fluoride.

 

[WhatCouldGoWrong71]

@mcarroll @Randy Holmes-Farley

I’ll let you guys chuckle… (AW=AquaWiz)

I have stepped my CARX’s PH up to 6.51 - 6.55 that’s +.20 and I have dropped my feed pump from 95 ML/MIN to 65 ML/MIN (I have to do a dKH reading, I haven’t in 2 days on the reactor).

I have taken a whopping .20 out of DKH. But what I have found was a sweet spot for PH. New PH probe (2 weeks old). On the PH graph the dip is where I had to refill my kalk mixer. I found this really interesting. I have a very well ventilated fish room that I’m not in until after 7pm at night. I think I am going to just leave alone right here…

 

[Randy Holmes-Farley]

Those values all seem good to me. :)

 

[mcarroll]

Agreed!