**fish dying?? Please help!!**

[Spark326]

Hi everyone

I have a 30gallon tank, running for 4 months.

Nitrates nitrites all nearly 0, pH 8.

I have a Rainford goby, 2 clownfish, bicolored blenny, fire shrimp, emerald crab,  pistol shrimp and yellow watchman goby.

I have 3 issues.
I added Chemiclean 2 days ago due to a cyano algae outbreak which has all gone away after treating. I did the 20% water change as recommended today. I had heavy aeration via air stones and wave makers during Chemiclean period.

(Issue 1) 2 days ago, my long nose hawk fish that  is normally very active and has a voracious appetite, stopped eating. For the first 24hours after dosing chemiclean, he just sat perched on the rocks as he normally does but did not take any food.

Today morning (2nd day of chemiclean in water), he was on the sand, which he normally never is.

 

Upon looking all over R2R and other forums, I decided to put him in QT and dose about 1.75 of Coppersafe.

I just saw he has thing stringy white poop and I’m not sure if it’s the one that others are describing when fish have intestinal parasites. (Image below)

Can someone take a look and please give me your opinion.

 

(Issue 2) I think all other fish are good. I’ve noticed the blenny and 2 clownfish have been scratching on the sand occasionally for the past few weeks.. so maybe it’s a matter of time before they get sick? 
I do have a lot of pods in my tank (all along my glass). I identified them after looking at several identification photos. I read a heavy pod population can cause the fish to scratch. 

So I’m not sure if they have flukes or another parasite or if they’re just irritated by the pods. They have been eating and acting perfectly well.

 

(Issue 3) One more thing: About 12 hours after dosing Chemiclean, my goby and pistol pair separated. My goby was out of the hole he normally peaks out of and wandering around the area. The holes in their cave were all blocked off with sand. Upon lifting the rock and sand, pistol was not to be found. But a nessarius snail was there. Could it be the snail ate the pistol? 

 

I know it’s a lot but I am really worried.

Any advice would be greatly appreciated.

[Humblefish]

The problem here is by dosing Chemiclean you introduced an X factor, which may be the problem and/or it's stressing your fish enough for a latent disease to manifest itself.

 

The first thing I would do is run carbon to pull any remaining Chemiclean out of the water, and also watch your fish closely for white dots/spots. The latter would suggest excess mucous is forming around where parasite trophonts are actively feeding on the fish.