HELP!!!! low PH killed fish?

and i did fallow the instrustions and compare it to the card,

 

is your tap water softened?

A water change shouldn't cause these problems. Did you do anything else to the tank? Is it getting enough aeration, is there lid on it?

 

The PH is not raising.... And they o not look good at all,

 

There is no lid on it, and all i did to it was a water change and im not sure if the water is softened., The fish and Corals have been fantasitc, we watch them every night, they were fine, and now this morning at 5am they look so stressed

 

what equipment do you have on the tank?

If you have a airstone I would add it now.

also I would test ALK again to be sure.

 

I used a dechlorinator

 

My powerhead will push air into the tank with the tube attached how long should i leave it on?

 

I had already assumed you did.

the airstone is for PH. high co2 levels decrease PH.

 

definitely as long as the ph is low.

 

two other things.

I would not use tap water.

I would not keep a lionfish with clownfish, lionfish would eat them eventually.