help with my reef tank

[Reefhelp]

HI, im fairly new to the hobby.

I have a reef tank just over 8 months old. Ive never tested my reef tank and have always hoped for the best until now. I have alot of corals that have died (Zoa/ Goni / Hammer/ Frogspawn / Favia / Acro / candy cane and even GSP) everything looked well when i first added corals after cycling but has been downhill since then.

I started dosing All for reef (5ml daily) and over the past 3 months, the torches and xenia look good but the utter chaoas zoa/ goni and toadstool barely open.

My parameters are quite high i think:

ALK - 13.4
CAL - 480/490
PH - 8.0
MAG - 1350

Please can I get some help on steps I can take to get my reef tank stable.

Im looking to stop dosing as cal and alk seem high. will do a water change.

 

[Cell]

Start testing regularly and stop dosing until you do so. Stability is your #1 priority and that's impossible to maintain until you actually monitor your levels and understand how much to dose to maintain them.

 

[Reefhelp]

Start testing regularly and stop dosing until you do so. Stability is your #1 priority and that's impossible to maintain until you actually monitor your levels and understand how much to dose to maintain them.

If I keep the levels how they are now. And just stick to the water changes every week. Will my corals get healthy. Thanks

 

[Reefhelp]

Pics of the waterbox 25

 

[Reefhelp]

salinity is sitting at 1.26. Was always 1.25 but recently increased it to see if the corals may become happier, but been the same. I use tropic marine salt and do a 10% change every other week.

Losing corals sucks,.

 

[Cell]

If I keep the levels how they are now. And just stick to the water changes every week. Will my corals get healthy. Thanks

Maybe yes, maybe no. Sometimes, once the damage is done, it's too late.