A little help with Frag Tank Parameters please.

[Fizbang]

Hey there folks,
I set up my Frag tank recently to use as a frag QT for my DT. It is a JBJ 20RL, although touted as a 20 gallon it only held about 16 gallons of water. I used a mix of my DT water and fresh mixed RODI with Instant Ocean. I added some biomedia and Cheato from my DT. I added 7 small frags consisting of a Florida Rhichordia, a zoa frag with about 25 small polyps, a zoa frag with about 6 small polyps, a hammer, a duncan, toxic splatter moon coral, and a small acan. It has had the corals in it for about a week and a half. Other than about half the polyps on the larger zoa colony not opening everyone looks happy and healthy so far. My questions involve dosing kalk and other things and my current parameters. So on the the actual numbers.

At start up
Am 0
Nitrite 0
Nitrate 0
Po 0
Calcium 400
DKH 9
Mag 1300 ish
PH 7.5
Sal 1.025

I started adding some kalk to my RODI top off water approx 3/4 teaspoon per gallon.

Stats now
AM .50
Nitrite 0
Nitrate 5 - 10 hard to tell the color difference
P0 0
Calcium 380
DKH 12
Mag 1140
PH 8
Sal 1.026

I guess my questions are why did my calc and mg drop with just softies and lps and my dkh skyrocketed. Do I need to dose Calcium chloride and MG? I assume I need to adjust my kalk mix down a bit to bring DKH down a little.

 

[Brew12]

Hey there folks,
I set up my Frag tank recently to use as a frag QT for my DT. It is a JBJ 20RL, although touted as a 20 gallon it only held about 16 gallons of water. I used a mix of my DT water and fresh mixed RODI with Instant Ocean. I added some biomedia and Cheato from my DT. I added 7 small frags consisting of a Florida Rhichordia, a zoa frag with about 25 small polyps, a zoa frag with about 6 small polyps, a hammer, a duncan, toxic splatter moon coral, and a small acan. It has had the corals in it for about a week and a half. Other than about half the polyps on the larger zoa colony not opening everyone looks happy and healthy so far. My questions involve dosing kalk and other things and my current parameters. So on the the actual numbers.

At start up
Am 0
Nitrite 0
Nitrate 0
Po 0
Calcium 400
DKH 9
Mag 1300 ish
PH 7.5
Sal 1.025

I started adding some kalk to my RODI top off water approx 3/4 teaspoon per gallon.

Stats now
AM .50
Nitrite 0
Nitrate 5 - 10 hard to tell the color difference
P0 0
Calcium 380
DKH 12
Mag 1140
PH 8
Sal 1.026

I guess my questions are why did my calc and mg drop with just softies and lps and my dkh skyrocketed. Do I need to dose Calcium chloride and MG? I assume I need to adjust my kalk mix down a bit to bring DKH down a little.

I would be surprised if you needed any kalk in your system right now. My best guess is that what you are seeing is either a little precipitation or just testing kit error.

What is your alk drop per day if you don't use kalk in your RODI?

 

[Fizbang]

I would be surprised if you needed any kalk in your system right now. My best guess is that what you are seeing is either a little precipitation or just testing kit error.

What is your alk drop per day if you don't use kalk in your RODI?

I don't have an answer for you on that.

I starting dosing a bit in anticipation of getting more corals and to bump all those numbers up just a bit, I was shooting more for calc at 420, mag at 1400, dkh 10, PH 8 or a bit higher.

 

[Brew12]

I don't have an answer for you on that.

I starting dosing a bit in anticipation of getting more corals and to bump all those numbers up just a bit, I was shooting more for calc at 420, mag at 1400, dkh 10, PH 8 or a bit higher.

Kalk is a very challenging way to correct for alk and calc. It is much better to use to keep things stable. It is also very important know your demand prior to setting up repeated dosing such as with Kalk in an ATO.

I also recommend against trying to change pH. There are only 2 components that impact pH which are alkalinity and CO2 content. If you keep alk stable that only leaves CO2. Kalk can give a small pH boost by removing CO2 from the water but if you don't have enough alk demand to keep alk stable it can cause issues. If you want a higher pH I would recommend running a CO2 scrubber on your skimmer inlet or via an airstone if you don't run a skimmer on your system.

My advice would be to clean out your ATO and go back to RODI. Measure Alk every day for a week and see how much it drops. Once you know how much it drops then you can get an idea of how much kalk you need per day to maintain alk steady. If you know this, and have a rough idea of how much water you evaporate every day, you can figure out how concentrated your ATO water needs to be.

Here is an excellent calculator to use to help.
http://reef.diesyst.com/chemcalc/chemcalc.html

I hope all of that makes sense. Let me know if I confused anything.

 

[Fizbang]

Kalk is a very challenging way to correct for alk and calc. It is much better to use to keep things stable. It is also very important know your demand prior to setting up repeated dosing such as with Kalk in an ATO.

I also recommend against trying to change pH. There are only 2 components that impact pH which are alkalinity and CO2 content. If you keep alk stable that only leaves CO2. Kalk can give a small pH boost by removing CO2 from the water but if you don't have enough alk demand to keep alk stable it can cause issues. If you want a higher pH I would recommend running a CO2 scrubber on your skimmer inlet or via an airstone if you don't run a skimmer on your system.

My advice would be to clean out your ATO and go back to RODI. Measure Alk every day for a week and see how much it drops. Once you know how much it drops then you can get an idea of how much kalk you need per day to maintain alk steady. If you know this, and have a rough idea of how much water you evaporate every day, you can figure out how concentrated your ATO water needs to be.

Here is an excellent calculator to use to help.
http://reef.diesyst.com/chemcalc/chemcalc.html

I hope all of that makes sense. Let me know if I confused anything.

It makes great sense.....thank you.