Two clown fish died today

[tlcphoenix]

I have a 38g saltwater tank that is about 3 months old. It had two clowns, 1 gramma, 1 goby, 1 small GSP.
I recently had an issue with some brown stuff all over the tank which I cleaned but then stopped as I figured it was the ugly phase.
During the most recent water change I raised the water level to a point where the HOB wasn't producing bubbles as the water enter the tank. I figured my wave maker had sufficient surface agitation so it wouldn't be a big deal.
One of the clowns yesterday started swimming right by the intake and then the other joined it. This afternoon they both died shortly after each other. The Gramma and Goby are still alive.
My wife determined it might be O2 related and tossed in air stones and took the lid off. She then tested the water which is included in the images

Am I missing something? Did they get starved of O2? I have had them for almost 2 months now with no issues. Eating fine, moving around fine, then this...

 

[Jay Hemdal]

I have a 38g saltwater tank that is about 3 months old. It had two clowns, 1 gramma, 1 goby, 1 small GSP.
I recently had an issue with some brown stuff all over the tank which I cleaned but then stopped as I figured it was the ugly phase.
During the most recent water change I raised the water level to a point where the HOB wasn't producing bubbles as the water enter the tank. I figured my wave maker had sufficient surface agitation so it wouldn't be a big deal.
One of the clowns yesterday started swimming right by the intake and then the other joined it. This afternoon they both died shortly after each other. The Gramma and Goby are still alive.
My wife determined it might be O2 related and tossed in air stones and took the lid off. She then tested the water which is included in the images

Am I missing something? Did they get starved of O2? I have had them for almost 2 months now with no issues. Eating fine, moving around fine, then this...

It could have been low oxygen/high carbon dioxide. During darkness, the algae in the tank takes up oxygen and releases carbon dioxide. If you don’t have good aeration, it can cause issues. Gobies are more resistant to this, I don’t know about grammas.

Did the clowns die with their mouths open?

Edit: I just saw they died in the afternoon? That is less likely to be an oxygen issue

 

[tlcphoenix]

Not sure about mouths open, wife found them while I was at work. The goby is a fairly new addition and the water color and brown stuff started after he was added. Good that explain anything? He has been stirring up the gravel, which i wanted him doing.

 

[Fishy888]

Sounds like there’s a mixture of fish poop, uneaten food and detritus, all rolled up into one, and accumulating in your sand bed. Been there, done that.

API is notoriously unreliable. I would get an ammonia test kit. I’d also get a nitrate kit and a phosphate kit. Go with Salifert. They’re not too expensive to start off, and they’re far more accurate than anything API. Eventually you’ll want a kit for calcium, alkalinity and magnesium, but I wouldn’t worry about those right away.

It could still be an oxygen issue if a bacterial bloom occurred. I’d add as much aeration as you can until things settle back down. If it’s practical, I’d do a 50% water change tomorrow morning, and in a couple more days do another 50% change. Stir up the sand bed when you do the water changes so you export as much of the gunk as possible.

 

[Mr. Mojo Rising]

I don't see a powerhead in the tank and hard to believe there is one in there, it must be too small, the water looks stagnant. That little tetra hob filter does nothing at all for your tank. IMO you need better equipment. The nitrates look very high, how frequent are your water changes? There is very little rock in the tank, I would want more.

IMO you need a pair of decent quality powerheads to move water and help with surface agitation to help oxygenate the water, the tank also needs some kind of proper filtration and more frequent water changes, and more rock to establish territories. Good luck

 

[Jay Hemdal]

Not sure about mouths open, wife found them while I was at work. The goby is a fairly new addition and the water color and brown stuff started after he was added. Good that explain anything? He has been stirring up the gravel, which i wanted him doing.

From what I can see, the brown material is mostly algae. Aside from that low oxygen issue, although it looks ugly, it won’t harm fish (it can harm corals).

Can you get some closer shots, and maybe some video of the remaining fish?

 

[Fishy888]

I don't see a powerhead in the tank and hard to believe there is one in there, it must be too small, the water looks stagnant. That little tetra hob filter does nothing at all for your tank. IMO you need better equipment. The nitrates look very high, how frequent are your water changes? There is very little rock in the tank, I would want more.

IMO you need a pair of decent quality powerheads to move water and help with surface agitation to help oxygenate the water, the tank also needs some kind of proper filtration and more frequent water changes, and more rock to establish territories. Good luck

I totally agree with this as well! You really could use more filtration, particularly biological, ie more rock.

I think it would also benefit you to have a sump as well. That would allow even better biological filtration and a place to put a skimmer and heaters so your display tank isn’t cluttered with equipment, which takes away from your display.

 

[slingfox]

The water looks in very very very bad shape if it is that color in real life. You should not have any livestock in water that looks that polluted.

For HOB are you running the Seachem Tidal50? If so, that is the unit I run on my 10 gallon saltwater quarantine tank. It is not something I would want to run by itself on a 38g reef tank unless I was rinsing out the chamber biomedia every few days and doing sizable water changes every week.

The brown growth everywhere described sounds in dinoflagelletes. That grow is very toxic and can kill livestock (typically only clean-up crew like snails but if very polluted it could affect fish too). During the ugly phase you often need to clean more rather than less.

#1 issue is get that water swapped out if it truly look brown like that in real life! Then add some permanent aeration or plan to keep the airstone in there permanently.

 

[Garibaldimon]

It could have been low oxygen/high carbon dioxide. During darkness, the algae in the tank takes up oxygen and releases carbon dioxide. If you don’t have good aeration, it can cause issues. Gobies are more resistant to this, I don’t know about grammas.

Did the clowns die with their mouths open?

Edit: I just saw they died in the afternoon? That is less likely to be an oxygen issue

I been told so this isn't my advice but I follow! Probably isn't a reason to put airtime in marine tank just add another powered? IS this a correct obsetvation