Low Kh and Calcium?

[The Kraken]

My 4 month old reef tank is doing great. All animals seem to be thriving. Most corals seem happy. My new elegance coral seems to close up frequently though. I have been having trouble with my Reef Octopus 150 Calcium Reactor. My calcium levels have been low for the past 3 weeks (like 200-250 low). I'll start dosing calcium supplement until I can get the reactor figured out. However, my Kh is always low, like 4-6. Dose with Reef Builder carbonate alkalinity raiser twice a week and can't get it above 6 to save my life. The elegance coral is only a week old in my tank but it has never been fully open after the first two days of being in there. Any suggestions? What's a good Calcium supplement? What's a good way to raise the Kh and keep it there? I do water changes about every 2 weeks, 20% (30 gallons). I use only RO/DI H2O. Thanks for your help.

 

[ccCapt]

I would definitely question the accuracy of your calcium test kit. It's almost impossible to have a calcium reading that low. A good calcium supplement is Kent's Turbo Calcium.

How much Reef Builder are you dosing and how big is your tank? According to the directions on Seachems site, it takes 3 grams (1/2 teaspoon) to raise the alkalinity 0.7 dKH for every 40 gals of water. A cheaper alk supplement is plain old Arm&Hammer baking soda.

Have you ever tested your magnesium levels? What is your pH?

Here are a few good article that I highly suggest you take the time to read through.
Chemistry and the Aquarium
A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com
An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com

 

[The Kraken]

Excellent articles. Thanks! I think that will help my situation greatly. Wish this [moderator edit] calcium reactor would work right though. Already ordered new test kits and will try the new dosing regimen in the article. Seems fail-proof. Although I bet I can give it a good run for its money! LOL

 

[Greenmaster]

What salt are you using?
You might want to look a switching salts.

 

[The Kraken]

I use Instant Ocean Reef Crystals. How do you dose your alk/calcium? Dosing pumps? Drip containers? Syringe? What's the best way?

 

[ccCapt]

What brand test kits are you using?

If you are using Reef Crystals, you calcium test kit is definitely wrong. RC usually mixes to about 490 ppm calcium. I would also question your alk test kit as well since RC usually mixes to around 13 dKH (4.6 meq/l), unless of course you are already reading your alk test in meq/l.

You can use dosing pumps, but I just add the amount I need in a measuring cup and pour it in the tank in a high flow area.

 

[The Kraken]

So got salifert test kits now. Ca is 320. dKh 9. So u guys were right, my test kits were bogus. Been supplementing with seachem calcium until I get my ca reactor figured out. Thanks everyone! Mt elegance coral has bit the dust I think though. It looks bloated and stays mostly closed and is sloughing off "stuff". Any hope for it?

 

[mr_X]

elegance usually don't do well in captivity, unless you get a specimen from aussie. you probably had one from indo, and it may very well be nothing that you had done/didn't do.