Would you raise the alkalinity? (Many new corals)

[Nadiaa]

I suddenly measure a rather high content of both calcium and magnesium, despite the fact that I do not add these substances to the aquarium, and use the same salt that I have always used. My tank is about 3 months old, but startet up with live rock from an already well running tank.

Besides that, I have been lucky enough to be able to buy quite a few interesting (I think) corals, from an aquarium that had to be closed down, and also a mussel. I thought I would add "All for reef" now that I have added some more demanding corals, but I dare not because of the high content of calcium and magnesium.
On the other hand, my alkalinity is on the low side, so I have to raise it. Or would you? Maybe with the AF KH buffer?

For the last few weeks I have been adding plankton (Synechococcus with zooplankton from Plankton24) to help my Cyano attack a bit, but this shouldn't affect these values, should it?

My values:
Nitrates = 7.2
Phosphate = 0.08
Alkalinity = 7.8
(I use the Hanna test for these)

(I use Salifert for the below)
Calcium = 460
Magnesium 1470



Do you have any suggestions as to why I suddenly have such high values?
Now, I know these values are not TOO high, I am just wondering WHY they are on these levels without me dosing anything.

I have attached a video of the new corals. I think it definitely seems like they did well, despite the move and that they are thriving and looking as they should. I may be running out of space now, but you know how it is

 

[Jekyl]

Numbers aren't really concerning. I would verify testing as a precaution though, including salinity.

 

[Nadiaa]

Numbers aren't really concerning. I would verify testing as a precaution though, including salinity.

Of course I forgot to mention that my salinity is 1.025

 

[Jekyl]

Of course I forgot to mention that my salinity is 1.025

Just meant that maybe a second opinion might be worth it. Plenty of times where our tests give false readings in cases of unknown changes.