First post, calcium question.

[piperld]

Hello everyone,


I just wanted to thank everyone involved with this website(posters included of course) for helping teach me to care for my coral reef.

Having these beautiful animals in my home has been a wonderful experience, as I'm sure you all know.

Here's my question:
Why is my calcium always 450?

Since starting I've had my calcium tested monthly for calcium at a couple different LFS's. Every time it's tested it's, 450.
I'm trying to figure out why after 6 months, and almost never adding calcium (seachem complete, about 1/10 their recommended dosage) the calcium lvl still maintains at 450.
I've tested it after waterchange, between wc's (which are every month+). It just seems to stay the same.



Here's my tank, if you see any red flags in here, don't be afraid to let me know:

55gal
175 MH & 40w NO actinic
skimmer rated for 120 gal (only used on weekends)
1 402 aquaclear (on wavemaker)
2 201 aquaclear (on wavemaker)
1 214 powersweep (always on)
>1 rio 2100 (had to be removed, it just blasted my tank)
110+ lbs corraline/sponged covered LR (from several stores and local reefers)
3-4" live sand (again several sources)

about 30~ full size snails
(astrea, turbo, cerith, bumblebee, conchs, margarita, and a couple that came on the rocks and i dont know what they are)
about 20~ baby snails (cerith and turbos lay eggs)
about 20~ hermits
(blue,red,olive,green,etc)
(even seeing some baby hermits with baby cerith shells :) )
and a few different kinds of macro algeas

2 1" percula clowns
2 bulb anemones
2 Peppermint shrimp(constantly hatching babies)
3 small banded starfish
1 3" mandarin goby (eats almost anything)
1 1" blue tang
1 cleaner shrimp
1 small black seahorse (seems to stay fat on baby peppermints)
1 small pipefish (seems to like the peppermints too)
1 1/2" clown goby (hardly ever see it..)
1 anemone crab

I had a few hermits and snails die. I think everything being covered in corraline didnt give them much of a food source.
I've also lost a blue star and arrow crab :(

All of the livestock gets along really well.
The tang and perculas will swim across the tank together.
The clowns sleep and play in the anemones.
Pipefish and seahorse arent intimidated by the other fish.

I dont plan on buying anymore livestock. As the fish grow, and outgrow this tank, i figure i'll get a bigger tank or sell them back.

Unfortunately all of the most interesting animals seem to be the hardest to keep.

For corals i've been buying all frags,

few mushrooms and polyps at the rock bases.
colt, xenia (which doubles size every month), toadstool, couple ricodera, and a bubble at a 'mid-tank' level.
couple acropora's and milliporas at the top level of the rocks.

All of the corals have shown signs of growth since purchased :)


I feed my reef a wide variety of foods.
Live or spraydried phytoplankton every day or two,
rotifers and/or baby brine about once a week

I've also been using about 15 kinds of frozen food, bloodworms, brine, F1,F2, krill, etc. marine flake food, shrimp pellets, just about everything. I've been feeding these mostly based on reaction and general "belly" size. I do like to make sure everything gets something atleast once a week.

Waterchanges have been done about every month and a half. I've based it primarily on the nitrate level. When the test shows any change in color, i change the water.

I've been adding seachem reef plus, iodide and reef complete. I've been using the reef complete well under their recommended doseage. Primarily because my calcium seems to stay at 450.

Every month i run through a variety of tests with the local stores(some great stores here), alk, cal, phos, etc. They always turn out right where they should be.

Today I was told my alk was a little low but acceptable. (sorry dont remember the exact numbers). So i got some seachem reef builder to raise carbonate alk. I'll be testing it again in the next week or two.

Well, thats pretty much my tank. Thanks for reading :)

[mcbaes72]

1st of all, welcome to RC. I'm fairly new here myself.

2nd, wow...what a long post. And your livestock & amount of LR is just awesome!

After reading how your Ca doesn't rise or drop, but stays level at 450ppm, here's my guess-timate (based on my exp. because I'm going through the same thing, too).

Since you have a 55 gal., have proper lighting (which most if not all your coral (frags) are photosynthetic), proper supplements (Seachem's products are very high quality & which provides some Ca such as Reef Complete) and so forth, I believe your Ca++ level is stable at 450 ppm because your corals aren't using it up fast enough, even though you're dosing it so infrequently. Also, Magnesium and alk/KH are also involved in keeping Ca at proper levels. BTW, since you didn't have any #'s to provide, keep in mind that NSW levels for Mg is @1300 ppm & NSW levels for alk is @2.8 meq/L or @ 8 dKH.

To share a similar exp., I have a 30 gal. reef (w/ fish, inverts, LPS & Soft) & I use ESV's B-Ionic alk/Ca supplements. My Ca++ stays @ 500 ppm, my alk/KH is @ 3.8 meq/L or 10.64 dKH & my Mg is @ 1350 ppm. I do weekly water changes of @ 10% and I dose alk/Ca once or twice a week below the recommended starting dose. But in the last two weeks, I haven't added any alk or Ca supplements and my Ca is still stable at 500 and my alk dropped a little to 3.6. Based on these results, my conclusion is the Ca that's absorbed by the corals and removed by protein skimming is being replaced only by water changes.

But in your case, you don't even do weekly water changes. So, once again, I believe yours Ca isn't being used up as quickly and when you dose Reef Ca or Reef Complete (below recommended dosage), it's still enough Ca for your tank inhabitants.

I wish I was better educated in Marine Biology or Chemistry to give you a more scientific explanation, but IME, this is the best I could come up w/.

I hope that helped a little (& also to let you know that you're not the only one who doesn't use Ca often, yet your levels are stable). In a way, that's good news on how we can keep our Ca levels up. Some reefers have trouble keeping theirs above 400 ppm. So, I guess we're lucky in that aspect. :)

-Michael.

[tyoberg]

mcbaes' comments are good.

A few more:
calcium test kits are notoriously unreliable--I doubt the LFS has anything more accurate or sophisticated than the rest of us do. It may be a good idea to run some water to another store and see what they get.

Magnesium does play a part in calcium solubility. Low magnesium will limit your calcium levels, but there isn't much in the tank that consumes magnesium. If you do somewhat regular waterchanges, it'll never be a problem.

Ty

[Agu]

You don't have a lot of calcium using organisms in your tank compared to most tanks. That and water changes might explain the ca stability.

Agu

[piperld]

Thank you for all your replies,

I've been having my calcium tests done at 2 different stores with 2 different test kits. I figure it's reliable enough.

I was on the same line of thinking. (few calcium absorbing critters)

But with everyone so concerned with keeping calcium up, using calcium reactors etc. I suppose I was just expecting to see more of an impact, or well, just an impact of some kind on the calcium level.

Glad to hear there are other people with the same situation.

I'll wipe the sweat off my brow now :)

Thanks everyone :D