Do water change to reduce mg and ca and Increase your kh dosing then normal . Once mg is stable kh and CA are easier to balance .. Remember to check Ph as time go by ... Most important do it slow ..
i would buff up the KH slowly... like rocky said check PH as it goes along and leaves the rest alone .. or change some water daily (not too much) and buff up KH slowly
the light spread is just nice for 24in by 24in .. The intensity at the side is low, therefore for my 30in I can't put sps at the edge.. For 4 ft .. You need to put those low light requirement corals at the side ..
it is a no no using particle board... once touches water it will slowly disintegrate.. would rather you use solid plywood at least better then particle board if cost is a concern
1*3FT DE lighting 4 tubes.. selling at 200
Giving free use and not so new tubes colour of your choice
1*3FT DE lighting 2 tubes Selling @ 100
Giving free used and not so new tubes colour of your choice
1*2FT DE Lighting 4 tubes .. selling @ 200
DIY 2x2ft UV LED Never used before selling @ $50
PH-ORP controller selling @ $30
3-4 yrs old does not come with phobe.. cos phobe are too old.