Two Part Solution Problem- Help!
 

I am trying to tap into the collective wisdom here. I started my two part solution system a few months ago, as my kalkwasser additions no longer kept up with my growing coral collection. I automated the two part a month ago (before that I was doing it manually, as I was having issues with my Reefkeeper Elite head unit). I currently use Dowflake Calcium chloride and baking soda solution, dosed using BRS peristaltic pumps.

After some tweaking I found that dosing both CaCl and Alk solution for 36 minutes per day (split into four doses per day) gave me stable readings of 400-420 for Calcium and 7.5-8.5 dKH for Alk. Unfortunately a couple of my colonies started STN-ing. I checked the parameters again and I found the Alk started climbing over 9 dKH for no apparent reason. Yesterday I stopped adding Alk solution altogether, in the hope to let it fall naturally. I left the Kalkwasser dosing unchanged, i.e it keeps up with evaporation. This morning the Ca was at 440 and the Alk was 9.6dKH!

I can't make sense of this: I repeated the readings, tested for Mg which I found to be 1480. It doesn't make sense! I need some HELP!

Tank stats:

- 3 ft cube (150 gal) mixed display tank.
- Sump: approx 30 gal
- Skimmer: RLSS 6i
- Refugium: 55 gallon inline refugium full of cheato and live rock. Crawling with pods
- Corals: combo of SPS and LPS. Mostly small to medium frags.
- 10 Fish: 1 Yellow Tang, 1 Harlequin Tusk, 1 Copperband Butterfly, 1 Anthia, 1 Tamarin Wrasse, 1 Cleaner Wrasse, 2 Percula Clowns, 2 cleaner shrimp
- Params: undetectable nitrates and phoshates
- Reactors: ROWAphos, Biopellets, Kalk stirrer dosed via BRS dosing pump to keep up with evaporation

The tank was set up in April, when I upgraded and transferred all the live rock and corals from the 55 gallon that is now the refugium.

I started a tank journal which I sadly neglected:

http://www.canreef.com/vbulletin/sho...=107802&page=2

QI had these same problems when dosing Kalkwasser with two part. The Kalkwasser wasn't consistent in keeping stable parameters as evaporation rates can change. Anyways I dropped the kalk all together and just dose 2 part now. I bake my baking soda to maintain PH.

Currently I dose alk and calcium every hour each separated by 30 mins. My calcium never various from 430 and my alk 8.0dkh.

The high alk could of caused the STN some people notice when running biopellets this happens. I'd drop the Kalk and then figure out how much 2 part u need to dose. This is also a good read if u haven't already.

http://www.reefkeeping.com/issues/2006-02/rhf/

Your spike in Alk right now is the addition of an alkalinity supplement but growth has stopped , if your trying to drop your Alk cut the kalk altogether and dose calcium chloride only.

That last test is in the range of testing noise But none the less if things aren't using the Alk it won't drop and if Alk is being added it will only raise from there ;)

Kalk and Two Part
 

Thanks for your responses, guys. I guess I didn't make it totally clear: I dose Kalk in specific amounts (3 minutes of saturated solution every hour, i.e. 24 times a day). This keeps up with evaporation this time of year. I keep the kalk solution saturated via an Aquamedic kalk stirrer. Yesterday I dropped the kalk timing to 2min 40 sec avery hour. I have a separate topoff that adds straight RODI water to the sump if the kalk additions don't keep up with evaporation. I guess now that I dropped the kalk times, the ATO will add some water....

Yesterday I also unplugged the Alk doser from the Reefkeeper. I am still dosing the same amount of CaCl2 and the reduced amount of Kalk. I will test again tomorrow. If you have any thoughts, I'd love to hear them.

Thanks for that article DCW1SFU. I read it many times. What confuses me is the fact that the article says to always add the same amount of Ca and Alk. It specifically says to resist tinkering with the amounts. If I did that, my Alk would be through the roof!...

Imm not sure what your not understanding , yes you would dose equal parts when things are growing healty.

If you still dosing cackium now the difference between yesterday and today isn't testable , that's why we say dose on Alk number not calcium numbers the day to day testing for calcium can't be relied on as the testing noise is too wide . Alk isn't but if things stop growing (Rtn/stn)) your daily consumption of alkalinity slows thus the dosing amounts.

Regarding the kalk added it's an Alk additive (ca too) so if there's nothing to consume it then it will stay the or will slowly drop as animals use it.


The article say to use fixed amnts as the solutions are weighed that way , corals use Alk and cal at a fixed ratio of 1.4 dkh for every 10ppm of calcium for every 1ppm of mg


An average system uses about 1 dkh a day so testing on calcium consumption can't be done on the same day ( you can't test a 10ppm drop)


How much dkh a day is your system using ?

As Reefwars has stated dose equal parts based on your alk consumption. That's the real measurement you want to get right as it can play the most detrimental role in coral health. Don't get me wrong calcium is very important but it's much harder to damage your corals with slightly higher or lower then desired calcium levels. Once you have figured out your alkalinity demand you can start tinkering a bit with calcium.

Also the addition of either supplement has a lowering and balancing effect on the other. To get my levels right initially I tested daily at roughly the same time for about two weeks. Now if I need to its very simple minor adjustments.

I'm telling you though I think you will be more successful taking the kalk offline. It's great on its own, but hard to use with the addition of two part. I also was really reluctant to take my kalk offline but since I did I have had extremely stable parameters.

Is there a reason you are adiment on continuing to run kalk?

Fwiw calcium and Alk have no effect on each other although its common to her that they do , adding Alk will not lower or raise calcium and vice versa they are completely independent of themselves and one don't change the others number and technically can't ;)

I agree if your using kalk as a ph boost then sodium carbonate would be a Fine choice as well:)

You are right there is not a direct relationship that adding one will automatically drop the other. I looked into this further. I was misinformed.

I should note that This is only if we're talking about calcium chloride and bi/carbonate solutions though other Alk or calcium additives may be different , these two will only add what their supposed to and not affect the other:)

What's your Magnesium level at, I understood from what I have read and listened to on the BRS site your Mag level needs to be at at 1300-1500ppm for your alk& cal dosing to be able to adjust & stabilize properly. I am no expert just sayin. Might be worth looking into. :juggle: