I need help

Brief description of the problem.
I have been having an ongoing problem over the past few weeks with my parameters, mainly my calcium, magnesium, dkh and alkalinity. I just changed my salt, as you will read below, to try to help with these levels. However, even prior to me changing my salt, a few days ago 2 of my 4 fish developed white spots/blemished on mainly their mouth/face area and their chest/under-belly areas. I thought it was where they had scraped up against the rocks, since I just added a vortex mp40, and overnight the spots seemed to have gone away, but then the spots appeared again the next day and have stayed and one of my fish, a scooter blenny, died, and it didn’t even have the white spots, only my blue hippo tang and my purple tang have the spots. I also have a coral beauty, and it has no spots at all. The remaining three fish seem to be ok and they are eating, but I am in desperate need of anyone’s help of what might be wrong, before I lose my other fish. I have had these fish for almost a year now and have never had a problem with them before. Also, my corals are looking better than ever, even though my levels are so out of whack, so I have NO idea what’s going on with my fish.
A picture(s) will also help.
PARAMETERS (important)
Temperature: 78
PH: 8.3
Ammonia: 0
Nitrite: 0
Nitrate: 0
Salinity: 2.025
dKH/KH/Alkalinity: off the charts
Magnesium: 1140
Calcium: 310
Phosphate: 0
Test kits you own: all of the above
Liquid or Strips: Liquid
Brand Name: API and salifert
Are they Expired?: no


Tank size? 90
Estimated total system? 120

Reef, fish only or, freshwater? Reef with fish

Current inhabitants? What and how many? Red and green monti, bird nest, tort, green slime, yellow cup, purple chalice, green favia, zoas, palys, frog spawn,
Clean up crew? 30 blue leg hermit crabs and 20 astera snails

How long has your tank been set-up? 1 ½ years

Substrate.
Type? sand
Depth? 2 ½ in

Live rock? yes
How much? 110+
Did you recently add some? no

Filtration.
Type? Overflow into micron bag, 15-20 gallon refugium with 2 ½” sand bed with 2 ½” mineral mud
Protein skimmer? yes
Do you wet or dry skim? wet
Maintenance schedule for filtration? 10% water change each week
Drilled tank/hang on back overflow? drilled
Sump/refugium. What's in it and how much? See above “type”
Macro? Yes What kind? Cheato, grassy leaf, live rock

Lighting.
Lighting type? MH 2x250W and 4x54W actinic
Age of bulbs? 5 months

Feeding
What? Krill, mysis shrimp once a day and nori every other day and oyster eggs for corals every 3 days.
How much? 1 sm block
How often? See above “what”

Water change schedule.
How much? 10%
How often? Once a week
What salt brand? I.O. now converting to Tropic Marine Pro Reef
Water source? 5 stage RODI

Additives/supplements used? Mrs. Wages pickling lime for calcium

Do you have a ground probe? no
What kind of flow does your tank have? Vortex mp40w and a k3. mag 9.5 return

Any additional info you would like to share.... Including anything different that you have done/not done.
I switched my salt and have added a few coral frags and just recently added to my clean up crew.

 

Is your SG reading really 2.025 or is that a typo?

 

Also is there any explanation of why your DkH is so high? Adding buffer to get ph up?

 

Your calcium and magnesium are low, that is probably what is throwing your alk high. Those three have like a seesaw effect, with magnesium being the balancer. Get the MG up to around 1400, and the ca up to about 450, and do not dose any alk, it should fall right into line.
Now, the spots are most likely ick. There are a few different ideas on how to go about treating it. Personally, I would leave them in there as long as they are eating and your water is good. As soon as they stop eating, then move them to a hospital tank and treat with copper.

 

im not sure.. but this will bump your question back up.

 

yeah the sg is 1.025 lil type-o. i do not add anything to the tank to for the ph. right now i am dosing some randys part a-b slowly to get the mg up and then i will start to hopefully see the others go up.
with the fish the spots come and go, im sure it is a kind of ich but i plan to wait it out and see how they are in a few days. they are always hungry so i will keep feeding.
the funny thing is that the corals in the tank are looking better than ever! its weird

 

when my mg gets around to be near or at where it needs to be what is the best why to dose cal?

 

over the corse of 3.5 hours with a drip per second or so it rose to 1260..... which is good and there is still about 70ml left over from the 500 that was in the doser..... any thoughts on the calcium?

 

bump

 

I just use liquid calcium dosed everyday. How much really depends on your tank and how much coral you have. Just do a little at a time. Give it an hour then test.