High Ca, low Mg help please

[adirondack]

Hi,

I have a 72 gal bow, set up for 3 weeks. Started with 4-5" aragonite sand, various grain sizes, 20 lbs of live rock and 20 lbs live sand from local aquarist, 20 lbs live sand from GARF, reef crystals, RO/DI water, 60 lbs of dry rock from marcorocks. Also about 15 small hermits and 15 small snails. The purple coralline is looking good, has really brightened up, a very small amount of green algae growing now. I haven't added any supplements yet, and I am not yet using a skimmer. No mechanical filtration. Water is clear, looks good. Initial chem readings:

Date: 8/17/2009
Temperature 78 F
pH 8.0
Salinity 1.023 SG
Alkalinity 3.89 meq/l
Calcium 420 ppm
Nitrate ?
Phosphate ?
Nitrite ?
Ammonia 0 mg/l
Magnesium 1050 ppm

Today's readings: 8/26/2009

Temperature 78 F
pH 8.35
Salinity 1.0235 SG
Ca hard/Alkalinity 2.97 meq/l Salifert
Calcium 520 plus ppm OFF the scale... API
Nitrate 10 mg/l (could be 5, colors are so close...) API
Phosphate 0.5 mg/l API
Nitrite 0.25 mg/l API
Ammonia 0 mg/l API
Magnesium 930 ppm Salifert

The calcium is off the scale, the Mg is low. Is this a short term problem, should I just wait a few days to see where things go?

Any help would be appreciated

Thank you

[Billybeau1]

Well, I think you should first concentrate on getting your specific gravity up to at least 1.025

I would prefer to see it at 1.0264 or 35 ppt

This will increase your magnesium level due to the addition of more salt per gallon.

I would discount the calcium number for now and let things settle. :)

This is, of course, if you are starting a reef tank. If it is going to be a fish only, 1.023 is fine. :)

[adirondack]

Yes, this will be a reef aquarium, eventually. I plan on adding a few more inverts when things settle a little more. I think I read on this forum that only bad things happen quickly in a reef aquarium, so I'm being slow. I'll monitor for a few days, see what happens.

Thank you

[Billybeau1]

That is a good attitude to have. I'm sure you will be successful.

Your welcome :thumbsup: