Sick/dying coral help

[carey]

so I've had the 3 corals in the pictures below for over 6 months, probably longer and I just now am having a problem with them.

The candycane has receding flesh on two heads, it is middle of the tank with medium flow.

The birdsnest was thriving and growing so well but about 3 days ago the flesh started peeling off. It is placed high in tank and high flow.

the third one is my blue clove polyps, I have at least 4 aiptasia's that are seemingly killing the coral. Not sure how to proceed with this one.

Ammonia 0, trites 0, trates 0-5, ph 8.3, temp 79, salinity 1.0255, calcium 425, alkalinity 8.0, magnesium 1200, phosphates .56.

I know the phosphates have to come down, but that shouldnt be causing the corals this kind of damage.

Any ideas or suggestions?

[redsea]

I am really sorry about that carey. I know that this is probably not the case, but it is all I have to offer. Do you think that there could be some parasite/disease that was introduced on a coral? I know you use a coral medicine though, so that is probably not the case. I figured I would try though, I hope everything turns out ok.

[carey]

Thanks red...I use coralrx for my corals and they seem to be intact. :-( They are the only corals that are showing any issues, everything else is just fine. I have a pretty large bushy acorpora that is still doing well as well as my gonipora. I figured they'd be affected if it was something really bad. lol

[Rscomia]

How are you adding your kalk mix?

[carey]

It's in my ATO reservoir.

[Rscomia]

Is that all thats in there is your kalk mix and how much does it add at a time?

[carey]

I mix the kalk with ro/di water in a large bucket, let it mix for awhile then add it to my reservoir. I have the return section full before I do this so that the mix can settle for awhile.

I'm using 2 teaspoons of kalk per gallon of water and I don't mix in any other supplements in the reservoir.

[Rscomia]

Correct me if im wrong but you just started dosing kalk? The reason why I ask how much it adds at to your tank at what time is because a kalk mixture will have a ph of around 12 if its adding alot at once it could be causing a ph swing which may be affecting your corals which seemed to be fine until after you started dosing kalk right? I actually drip my kalk dose It usually takes me about 6 hours to add one gallon not saying that it should take that long but better safe then sorry I guess to make a long story short it is best to add kalk slowly

[carey]

Yep, the trouble started when I started the kalk. My ph has been pretty stable though, thats the one thing the kalk has done.

How do you know how much to add? is that 6 hours every day?

[Rscomia]

Testing daily you want to see what it takes to maintain your calcium I usually drip a gallon every night since my tank usually goes through a gallon of water a day and I do it a night since your ph is naturally lower at night I am using 2 tsp per gallon as the demand in your tank goes up you may have to increase the amount also you are using just the clear water in the middle of your kalk mix?

[carey]

Yes. I have the intake tube halfway down so it doesnt pull from the slurry on the bottom. I thought kalk's maximum saturation point was 2 teaspoons per gallon? How do you drip your calcium? Do you also supplement for alkalinity?

[Rscomia]

2 is the max it is a saturated solution just saying if you started with say 1 tsp per gallon to maintain your tank as the demand goes up you may have to increase the amount I built a cheap top off jug with a hole drilled in the bottom of it and a piece of airline attached to it with a valve in it to adjust the drip it probably didn't cost me $5

[mr_X]

i would stop dosing kalk and just do weekly water changes with a decent reef salt and enjoy your tank. i've always took care of my tanks this way and never had problems.