Low Alk high Calcium

[yerboy]

To start i have a 20L tank 4gallon HOB fuge and 12gallon sump so more then likely after LR and such about 28-30 gallons of water.
Over the past few weeks my calcium has been very high 500+ , im sure its been this way for a while i just haven't been testing it until now. Tuesday i did a 7 gallon water change and tonight i tested and im showing 480 calcium and alk at 2.74 meqL my other readings are
Temp 81
PH 8.1
Salanity 1.025
Ammonia 0
Nitrite 0
Nitrate 0
Phosphate .01
Should i be alarmed ? The only thing in my tank that seems to be unhappy is my 2 head duncan thats starting to loose the fleshy stuff on its shaft everything else seems fine. I have no SPS in this tank and only 1 clam, a few LPS with mostly zoas and other softys.
Lighting is a 175w Halide and 2x27w pc actinic.
Also im using Oceanic salt and after a quick google i found a few post of people claiming that oceanic has 520+ calcium and low alk "didnt find a post that gave exact alk readings" right out of the bucket.
Any Advice?

 

[geoj]

If you drop the salinity to 1.024 that should lower the calcium a bit. I have not had much xp. with very high calcium but it may stress some corals. If things don’t look better with lower salinity you may want to try a different salt. Phosphate .01 where is this from?

 

[aquaguy24]

i also use oceanic salt but i don't have this problem...alot of other ppl who use this salt do experience ur problem but they say it has no ill effects on their tank...

 

[yerboy]

Im sorry phosphate was .03 had to pull my color chart back out and look.