cloudy water wont clear?!

[jamesjre]

hi i have had my tank for about a year and a half, and have never had a problem with my tank before, water is always clear and regular water changes (20-30%) every 2 weeks, never lost a fish until last week. all of a sudden my tank clouded up over night and just wont clear, everything is running so its not like anythings been taken out, i lost 1 of my angels last week which really annoyed me but i suppose it comes with the hobby , then i noticed that my regal tang had red spots around its head. all the test levels are spot on, the tang looks like it is getting a bit better but was just wondering if any1 knows why this would happen and how to now clear my tank as the water just wont. i have already done a 20% water change which i was hoping would help but it just hasnt.
thanks in advance

 

[dunc101]

I know you said you checked for parameters, but which exactly? Did you check to make sure you didn't have ammonia? Sometimes cloudiness can come from a bacterial bloom. Your tank seems very mature, so hopefully you did not encounter a mini cycle.
Are you running any carbon? Also, have you changed or are you using a new batch of salt?
Have you added any new fish, or an anemone, perhaps? The red dots could be stinging. Red dots can also be a sign of ammonia poisoning which would go hand in hand with the cloudiness (bacterial bloom from ammonia converting to nitrite/etc). Just some thoughts.

 

[jamesjre]

i have checked ammonia, ph, nitrite and nitrate and all readings are the same as they always have been, have just tested again to be sure of ammonia and is sill fine, so i am confused as to what has happened, i haven't added fish in the last 4 months, i always get my water for my tank from the same shop, unless they have changed anything with it but i cant think why not if they are running tanks themselves, my mate seems to think i had an ammonia strike which would explain the dead fish, but i dont see why it would randomly do that, will those red dots on the tang disapear on there own then? also noticed it rubbing against the live rock every now and then, which is a worrying sign but also the cloudiness just doesnt seem to wanna budge, would you say doing another water change might possibly help? thanks

 

[dunc101]

Can you take a pic of the tang? Do you have a deep sand bed and did you by any chance disturb the sand bed? I have seen that cause ammonia spikes before. If you are not running any carbon, I would run some as it may help to clear the water up.

 

[jamesjre]

il try and take a pic of the tang now, and yer i am running carbon, im just hoping it will clear now if i give it some time, but its just annoying as it doesnt look very nice at all.

 

[jamesjre]

not a very good picture, as they move so quick

 

[dunc101]

Yeah, I can't really tell anything from that pic, lol.

 

[BobbyV]

Uv has excellent results. Consider the internal twist design in which water actually passes through the device.

 

[gskidmor]

if you dose VVS or run some type of bio-reactor, stop it - you could have a bacterial bloom - and if it is, the UV would help.

You didn't add new GFO or new sand or greatly increase flow preceding the event did you?