what to add to increase calcium?

[chercm]

i am using Aqua pharm skeleton builder pro series - calcium

does this help?

my calcium level is at 400 now.

[iantoh]

bro, calcifying corals utilise alkalinity and calcium at roughly this ratio: 2dkh alkalinity, or 1meq, to every 10ppm of calcium. so youll need to maintain both alk and ca inorder for the corals to be able to obtain either, as they are absorbed in tandem to form aragonite for skeleton building.

think the aqua pharm skeleton builder is a calcium chloride solution, so it should raise your calcium no probs. 400ppm is fine if you can keep it constantly around this region. natural sea water is generally only about 360-380ppm.

cheers,

ian

[chercm]

i thought from the package it mentioned that sea water is 400-450

[Qxnviolet]

Anything from 400 to 450 is fine....sometimes its not so advisable to add too many additives. If you still find it low, there are lots of additives that can increase your calcium level. Any LFS will carry some of this products. Just ask around....4

[iantoh]

in our captive tanks, we generally maintain calcium at pretty high levels, up to 500ppm. in the ocean though, calcium rarely exceeds 400ppm, which is why corals grow relatively quicker in well maintained tanks because it is alot more easier to obtain alkalinity and calcium in our systems.

alkalinity likewise, is seldom above 7dkh in natural sea water, but we maintain alk at up to 12dkh, because that is the upper threshold- any higher and calcium will start to precipitate abiotically from the water column creating a cloudy effect. so the bottle's instructions merely recommend that you maintain elevated calcium levels in your tank.

though we think of hard corals as calcifying, they dont just need calcium. they need both alk and calcium to form aragonite, which is their skeletal material, so alk between 7 to 12dkh, and ca between 380 to 480ppm should stand you in good stead.

youll find that if you maintain, for example, parameters of 10dkh, and 300ppm calcium, that your kh will still fall in line with your calcium, at the ratio of around 2dkh to 10ppm of ca, as this is the binding ratio for calcifying corals, so the calcium is still obtainable at pretty low levels as long as alk is at ok levels. whereas if you have high ca at say 480ppm, but with alk of less than 7dkh, your kh will dip till about 4dkh after which your calcium will hover around 470, with neither parameter moving much thereafter as the coral is unable to use either, so best to think about them both together.

well, just my two cents ya. hope that helps.

cheers,

ian