Adding Kalk to a new tank with no coral?

[MiamiAG]

Hi -

I have a new tank sitting in a CO2 ambient environment that keeps my pH depressed. No option to keep a window open or run a skimmer air line to outside. At the moment, the tank is 1/5 months old and has no fish or coral. I'm breeding bacteria at the moment.

The pH now is averaging 7.65. Apex pH probe calibrated so it's as correct as that probe can be. I'm awaiting a handheld probe to just double check but this pH seems reasonable. BTW, I have done @Randy Holmes-Farley 's water cup test. I have high ambient CO2.

I have a CO2 scrubber running and started a refugium with cheato running at night for 10 hours. I do have proper aerating being driven by pumps.

I would like to get pH up to average of 8-8.1. I would like to start dosing kalk using my Apex DOS. I'm hoping this will move my pH up towards my goal.

My question is whether this is a good idea now rather than doing it after I add fish and coral? In other words, my logic is to get my system up to my target pH prior to the livestock to avoid any shocks. However, would the kalk cause my calcium and alk to increase too high as I have no consumption?

Would appreciate any thoughts to help me think through this.

Art

 

[KrisReef]

Your logic, to do it before you add fish or coral is very wise. Getting parameters stable before moving forward with livestock allows you to experiment with changes and see if there is a way to get proper pH in the raised CO2 environment, and to keep it stable at the same time.

Will it work? It will work better to test it/fix it before you add anything that will die/suffer if it isn't stable. Let's see what the rest of the folk have experienced, and how they overcame (or failed) with this. My fix was to fine tune my calc reactor so that I wasn't using excess CO2 that would enter the tank with the reactor effluent. The ambient air was not CO2 rich, just my set up wasn't very frugal with CO2 additions to melt the arragonite. Good Luck

 

[Nano sapiens]

Agree with KrisReef that it's a good idea to see how Kalkwasser works out in your system before adding sensitive animals.

Many people report Ca and Alk dropping in their systems, even without corals due to coralline, precipitation, bacterial activity, etc.). So you may find that maintaining 8.0+ dKh results in reef acceptable CA/Alk levels.

Trivia: Back in the early days before hobby test kits were commonly available we used to just use 100% clear saturated Kalkwasser as the top-off. Had no idea what any of the levels were, but it worked which was probably due to the systems being closed off with a top cover and/or hood, so evaporation (and the resulting Kalkwasser additions) were a lot lower than in an open-top reef aquarium.

 

[dstockwell]

I added a 1/2 dose of kalk, next day tested and calcium was raised more than I wanted. I just let it run course not adding any additional until test shows low.

 

[MiamiAG]

Hey thanks. One option is to just do it and test. Stop when I’m reaching the upper limits of Ca and Alk. I don’t believe this would harm the bacterial population so may be worth the good old try.

 

[KStatefan]

If you have no demand for the alk it will continue to raise at what ever rate you add it.

 

[BroccoliFarmer]

I had a small back and forth with Randy on this topic. Using kalk to raise your ph in a high co2 environment can cause you to raise you alkalinity to undesirable levels. You are better off with the outside airline to the skimmer or the co2 scrubber.

another good option, extend your display tank light schedule

 

[Randy Holmes-Farley Verified Community Expert]

Hey thanks. One option is to just do it and test. Stop when I’m reaching the upper limits of Ca and Alk. I don’t believe this would harm the bacterial population so may be worth the good old try.

Forget calcium tracking. It is alk that is very likely to become excessive quite quickly.

 

[MiamiAG]

Thanks. Photosynthesis is something I’m obviously lacking. Trying to get my chaeto to grow for that purpose but it’s not taking off because of the low nutrients in the tank.

My guess is that I have no choice but to add corals and fish now and then work on adjusting pH slowly. This is the only way to get photosynthesis and nutrients going that will take up CO2 and the additional alk from the kalk.

thanks for helping me think through this.

 

[Johnic]

Following along. I have a similar situation and I’m waiting to start my kalk dosing. I only have 3 fish and some coraline algae.
My concern is the precipitation of the calcium which can harden the sand into a rock which I did in my past setup. I over dosed Calc and the sand turned to a rock.