Advice on Calcium Testing

[benmorrow1978]

Hey all, I've got a simple question for those familiar with the Instant Ocean test kits and quite possibly the Seachem brand as well. I say Seachem as well because I've cracked open the Calcium Test kit box and it's identical to the Instant Ocean.

My question is; When I add my final reagent (#3), the directions state to add 1 drop at a time until the solution goes from red to blue. I've had the solution turn a dark purple, but never true blue. I'm not picky about colors... I do know the difference between purple and blue. So, when it hits a dark purple do I stop? My results never seem to go up, I've got lots of corals and I dose daily, but the results haven't changed (much if at all) since before I started dosing. I'm hovering right around 330mg/L. I'm switching from the Kent Calcium Chloride to Reef Builder/Reef Advantage soon to see if that gives better results. I always have a small dip in pH when I use the calcium chloride.

75 gallon tank
1- Open Brain Coral
Many xenia sp. and green Star Polyps
1 Frogspawn that just looks awesome
1 Sun coral that also looks awesome
various mushrooms
150# or so of live rock
1 bicolor blenny
1 super cool black clown, single stripe, orange belly
2 Skunk Cleaner Shrimp
1 Purple Firefish in quarantine (4 more weeks)
1 Peppermint Shrimp in quarantine (4 more weeks)

Most test results are good, no amm, nitrite or nitrate detected, Phosphates are just 0.2, salinity is 1.024 and temp is 79F, Alkalinity is a little low at 2.5mEq/L and I'm hoping the Reef stuff coming in will help with that too. Just really wanna get this calcium problem fixed ASNAP.

Thanks for your help and expertise!

Everything is healthy for the most part, the brain doesn't seem as full sometimes and I think that's the calcium issue.

[reeferbill]

Hi Ben ; I had trouble with Seachems reef advantage and I switched back to the 2-part calcium and buffer. I like ESVs brand best but Kents or 2-Little Fishes or Brightwell are all good products. I use an API calcium test kit and it only has 2-parts to it , 10 drops of reagent#1 and then count the drops of reagent#2 until the color changes and it does not matter if its pale or dark purple instead of blue because that is the color and its only a difference of one drop. Happy Reefing!!!!!!!!!!!

[Original Fin]

I use API calcium tests too...they are easy to read.

I'm looking into cost effective calcium buffers at the moment as well. Have used 2 part, and Kalkwasser...those can get pricey.

Calcium chloride is what you want. Check out this article...

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com

[MyNameIsJoe]

I've used seachem calcium test previously as well and had the same issue. Color would go to dark purple but never blue. I've done google searches on the subject and couldn't find an answer. Every time I tested i was really unsure about the the Ca levels being accurate so I bought a diff brand. I don't remember the name but its a 2 part liquid test and it goes from pink to orange. The change in color is instant and very obvious.
Never figured out the seachem, but glad I switched kits...