Please Help! I think my tank is in trouble!

[mystrybird]

Hello, I hope someone can help. Before I begine I will list the basics.
75gal tank running for 9 mo.
Nitrate 20ppm
Nitrite 0
Ammonia 0
SG 1.025

My problem started about 7 days ago. I noticed that my Royal Gramma's fins looked a little shredded. My first thought that something was picking on it at night. The next day I noticed browish red spots on the body (reminded be of bruising) & worsening of the tail fins. I checked my water & noted that my nitrates were up slightly & did a 10% water change.

The last 4 days I have also done a 25% water change daily & cleaned out filters & replaced carbon. Still no change in the Nitrates. Tonight I noticed that my red brittle star seems to be disinigrating around the disk. My P Puffer has random spikes up around the body & color looks odd in spots. I have also noted droped spines off of my pencil urchins during the water changes. My 2 yellow Tangs (yes I know... please do not yell at me) have recently started to fight & are causing stress to the tankmates. One of them has a large white spot on the tail fin, but I think it is from fighting & not from ICK. All fish seem ok & eating well except for the RG.

Without taking apart my rock, I have looked the best I can for any dead snails that might be the cause of the elevated nitrate.

The only recent additions to the tank have been invertebrates.
1 sand sifting star, 2 pencil urchins, 2 purple urchins & 5 astrea snails.

The only other thing that I should add is that my boys had some friends over just before the problem & I caught one of them around the tank trying to make the P puffer Puff up... They all denied putting any arms into the tank (teenagers..) but water was dripping down the front of the tank....

I am worried that I may have introduced something bad from the invertebrates 4 weeks ago, or some kid put something into the tank???

If anyone can help I would be very happy.. I can give more info on the tank & stock list when needed. I also have some pics of my RG & brittle star..
Thanks! M

 

[t11t5]

Take anything out that filters water, like foam, filter cartridges, etc. They hold nitrates and will release them into your tank...

 

[Cord]

I think the key is to replace or clean filters at least weekly. (I clean my cannister filter monthly and my nitrates are 0). Do you have a good skimmer? you could have a dead snail or something behind the rocks, or even a boring clam in the rocks that died, and the skimmer will help get that junk out of your water. Also, if you are not using RO water, you probably should be, but test your fresh makeup water for nitrates. I hope that helps.

 

[mystrybird]

Hi, Thanks for the replys.

I always clean out filter once a week during water change. except for the canister, that is once a month. I not not using ceramics or bio balls either. Am also running skimmer.

I have a RODI unit for water. I have tested both holding container & fresh makeup. Both test normal.

RG died as expected. The brittle star looks really bad this evening. I do not really think that it is even still alive & movement is likely due to whatever makes the pieces move for days after. Nervous system?? I am really bummed out about the star as it was reall old & the biggest I have ever seen. It was handed down to me from someone who had it in their tank for a few years.

Nitrates have always been 0 until I added 4 urchins to battle breakout on the rock. Perhaps they are doing too good of job. I think that tonight I am going to hold off on water change as it is adding too much stress to fish. & try putting 2 of the urchins & the sand star into a different tank to see if that makes a difference.

That said, I am more concerned that my RG was suffering from bacterial disease. My nitrates were never high enough to cause a big problem. I am at a loss to figure out what is happening.

Thanks, M