Fish keep dying, except starry blenny

[doctordox]

I hope that I am in the right part of the forum for this. Apologies if not! So long story short, in December I had a 3 month old tank, with a handful of clown fish and I added a starry blenny. All was totally fine, and suddenly in January, after I was aggressively cleaning the tank (I initially thought I moved things around too much), and I came in to my office where my tank is at and all of my clowns were dead, but the blenny is fine. So fast forward months later, Ive lost a bunch of Chromies and a Wrasse. My inverts, and Blenny have zero issues.

Every fish I add, dies within 48 hours.

Water tests totally fine really, but I had an algae breakout that was bad (now eliminated basically) and I think I had like zero nitrates in my tank because of that.

Could these fish keep dying because of a lack of nitrates in the water? IM so confused, and im starting to get upset over this. I love my tank. The Blenny is in heaven with the remaining algae, and he seems to be totally fine after all these months.

Ive changed my charcoal out multiple times, ive done big water changes. Any suggestions? Im very very confused as to what to do. Even local fish stores are a bit confused by why my water tests basically fine, but yet nothing survives.

Ive thought about just doing a huge water change, usually I do 10 % change. Its a 55 gallon tank, no sump just double filters and I dont do corals (yet).

I appreciate all and any responses!

 

[doctordox]

 

[doctordox]

 

[Bnutz]

Are you topping the evaporation off with salt or fresh water? That would cause high salinity. You should get some seachem prime for tap water

 

[doctordox]

Are you topping the evaporation off with salt or fresh water? That would cause high salinity. You should get some seachem prime for tap water

Recently I used salt water to top off, but im done doing that and doing only RO water

 

[jaganshi066]

Could the Benny be a killer? How is it that every fish does other than the Blenny, I know it’s weird but I saw some blennies that are crazy aggressive even killing tangs

 

[doctordox]

Could the Benny be a killer? How is it that every fish does other than the Blenny, I know it’s weird but I saw some blennies that are crazy aggressive even killing tangs

I could believe it. I dont know what to do if thats the case. HEs been alone for a while so It would make sense. Add more rock? Give more hiding spots?

 

[jaganshi066]

I could believe it. I dont know what to do if thats the case. HEs been alone for a while so It would make sense. Add more rock? Give more hiding spots?

I would just take him out, I have a flameback who bullied any new fish but after seeing how aggressive some blennies are (believe it or not) I would say my flameback is an angel

 

[doctordox]

I would just take him out, I have a flameback who bullied any new fish but after seeing how aggressive some blennies are (believe it or not) I would say my flameback is an angel

Only thing I would say is I had clownfish in this tank, i had 4 of them, and then he got put in. and maybe a month later all the clown fish died and got stressed and died. You may be right.

 

[Tamberav]

I doubt it was just aggression if you came home to 4 dead fish the same day/time. Perhaps the deep cleaning you did stirred up enough debris to cause some sort of bacterial bloom and suffocated them. All these fish may have perished from different things.

 

[mickeysreef <*))))<]

I agree that you should check your salinity and oxygen issues as well. that salinity probe if from Petco is notorious for being way off. also I don't see any powerheads?

 

[doctordox]

I agree that you should check your salinity and oxygen issues as well. that salinity probe if from Petco is notorious for being way off. also I don't see any powerheads?

theres one on each side

 

[doctordox]

I agree that you should check your salinity and oxygen issues as well. that salinity probe if from Petco is notorious for being way off. also I don't see any powerheads?

will check oxygen levels. i need to get a kit

 

[mickeysreef <*))))<]

will check oxygen levels. i need to get a kit

as long as you have adequate movement in the tank and on the surface, you should be ok as far as oxygen.

I don't know if there is a test kit for that but getting things moving is usually enough.

 

[doctordox]

as long as you have adequate movement in the tank and on the surface, you should be ok as far as oxygen.

I don't know if there is a test kit for that but getting things moving is usually enough.

gotcha, yeah, i got one power head at the surface, and i have another for movement through the tank. and the two filters do okay at surface agitation too

 

[Tamberav]

will check oxygen levels. i need to get a kit

You don't need to check this now... what I am saying is if there is enough debris disturbed it can cause a bacterial bloom which can rapidly eat up oxygen. This is generally a temporary/short lived thing and no need to test it. It is likely not an issue now but may be what happened to the clowns at the time.

Chromis are prone to urenoma which can also be internal, plus they like to beat each other up.

I am not sure what type of wrasse you had?

Also Starrys can be territorial but 4 fish dying at once means something more happened then a fiesty blenny. That doesn't mean he isn't responsible for a different fish but also we may just be pointing fingers. It is best to add fish when you have time around the house to monitor. Sometimes I even set up a cheap cam I can look on my phone to watch the fish. They are only 20 bucks on amazon. Besides, sometimes fish behave differently when we are not in the room.

 

[Jtk920]

What did your water tests come back at? Specifically ammonia?

 

[doctordox]

Okay, so I have worked on this tank, done a few changes, got my salinity down, ill test it here in a day or two after my cycle wraps up from adding a few more pounds of rock. Think I have it narrowed down to the blenny being territorial, so I rearranged and added some new rocks, in hopes that I can get some fish and just monitor his activity and worse case ill use a mirror to keep him destracted as Ive seen some people say to do around the internet

 

[dedragon]

what parameters are you testing and also is your LFS doing the testing and with what test kit? Usually bare minimum testing is ammonia, nitrate, phosphate, pH and salinity I would test the ro water from the LFS with a tds meter or have them do it in front of you at the store as I have heard of LFS being cheap and not replacing ro filters over time. One blenny is gonna have a hard time killing that many fish over 1 or 2 nights and you would see this aggression. You are finding these fish and scooping them out after as well, right? Asking because there could be a predator in the tank but again its very fast for multiple fish to be killed in such quick succession unless it is parameter related or if there is a parasite or infection going on in the tank as others have said. If everything is looking good now i would try another 1 clownfish, but if it happens again you may need to go fallow for a while and do an icp test on your tank water just in case

 

[Jtk920]

It doesn't pay to ask what the parameters are, I've asked multiple times and haven't gotten any. Nothing worse than people asking for help with a issue and not willing to supply the most crucial part of all, water parameters!

 

[Afaylenerich88]

Sounds like we have a newbie here, he/she is unaware that blennys are killing machines. They can and will kill any fish In there territory