Why do only some of my saltwater fish die off?

Question

I have a 150 gal tank. PH is 8, nitrate is 20ppm, nitrite and ammonium are 0. I have two types of shrimp, a sand sifting and a serpent star. Along with 4 different snails and 3 different crabs. All are living creat along with the four different corals I have. I have added fish and some live and some die. My clownfish, Cardinal fish as well as my basslet are living well, but I have lost a Jawfish, a foxface, two blennys and a copperbanded butterfly (I do have plenty of aiptasia in the tank for it to feed on). I cannot figure ot why these specific fish are dying and why some are not. The lighting is 3 250W MH along with PC and moonlights at night. The temp is between 76 and 81. There is a 55gal refugium. I also have a fluval 404 on the system. In addition, the tank has 100lbs of crushed coral, 200lbs of live sand, 250lbs of live rock and a proteint skimmer. The Ref has 90lbs of fiji mud, 50 lbs of curshed oyster, 50 lbs live rock and a protein skimmer. Any help would be great

Answer 1

It sounds like you've put some time and thought (not to mention $$$) into this system. Danielle brings up a good point, though. How long has the system been running? From your ammonia, nitrite, nitrate, it sounds like your tank has cycled, but maybe too many fish were added at one time? Your surviving fish are all hardy ones - the copperband can be touchy, though, "jawfish" and "blenny" hardiness can vary with the species. I'm surprised that the foxface died, because these are pretty hardy! One thing I did notice about your water parameter is that you pH is a little low - try bumping it up just a little to 8.1-8.4. This isn't the easiest to maintain, but a little kalkwasser will help keep it there and your snails, crabs, & corals will appreciate it. The nitrate isn't terrible, but could be brought down a bit with a water change. Do you have algae in the refugium? This will also help, and could help your pH if the lighting cycle is opposite that in the main tank (refugium light on at night). Also, you don't mention your salinity - should be 1.024-1.026 with the inverts.

Answer 2

Nitrate should be at 0ppm NOT 20ppm that could kill a lot of different marine fish.
Did you add a LOT of fish at one time???
That would be a BIG NO NO.
Clown, Cardinal and some basslets are pretty hardy fish and some people use them to cycle there tanks, that's probably why they are still alive.
Never add more than 1 or 2 fish at a time and then wait at LEAST 2 weeks before adding more.
Let your system catch up to the boi load you are adding.

PS: IF you listen to LEEMUCKO, your going to have a problem.
In a FISH ONLY aquarium high nitrate CAN be tolerated but is NOT recomended.
In your question, you STATE that you have CORALS and CRUSTATIONS and INVERTS.
"Although fish-only tanks may run at much higher levels, SOMETIMES with no ill effects, this is NOT recommended. In reef systems even a minor level of nitrate can cause damage as well as death to delicate corals, anemones and other invertebrates, as well as some crustaceans. The acceptable range of nitrate for reef tanks is 0.25 ppm, but not more than 5 ppm"
http://saltaquarium.about.com/od/nitratecontrol/ss/nitratecontrol.htm

"While nitrate is less harmful to our animals than ammonia or nitrite, it may cause excessive algae problems that affect the health of our animals.Algae require nitrate as a basic nutrient.If nitrate is allowed to accumulate in our reef aquariums in amounts above 5 ppm, it can affect the health of the corals that we are keeping by polluting the water and stimulating algal overgrowth of coral tissues.This waste product, the end product of the nitrification cycle, may be removed by such means as water changes, chemical adsorption, protein skimming, uptake by algae filtration or other organisms that can utilize nitrate as a dissolved nutrient source."
http://www.reefkeeping.com/issues/2002-06/dw/index.php

Answer 3

DanielleZ and Copperhead are the two best sources for salt water on this site. Listen to them.

Your nitrates can be even up to 40 in a salt tank. You do want to keep them as low as you can but 40 WILL NOT kill your fish. 40-80 in salt is fine.

Answer 4

Some fish are hardier then others. Clown fish, Damsels etc. can withstand much harder conditions then butterfly fish etc. That is why they recommend using these hardy fish for your tank cycle, which I think is cruel.

Answer 5

This is the perfect example as to why your Salt tank needs to MATURE. Cycling for 6 weeks does not mature a tank long enough to have higher end fish. Your tank needs to age from 6 months to a year.

What is happening is the bacteria development process doesn't stop after the initial cycle. Sea creatures require a higher amount of bacteria to survive. not only bacteria micro bacteria and macroalgae just to name a few. You are trying to recreate nature, what it has tanken millions of years to perfect in less than 6 weeks. It cannot be done.

This is the lesson new salt keepers find heartbreaking. Patience. Here is what happens when live rock is added to your tank and what it does.

When talking about live rock (LR), it is a misconception that the rock itself is alive. What makes it live are the many forms of micro and macroscopic marine life that live on and inside of it. The rock itself is only made up of the calcium carbonate skeletons of long dead corals, or other calcareous organisms.

There are different types of live rock. "reef rock" basically as pieces of coral or coral rock from outside the reef that have broken off and fallen to the bottom that then becomes covered with encrusting organisms, such as coraline algae and sponges. "Inshore rock" refers to as rock from inside the reef that has a tendency to be more dense and becomes covered with macroalgae, clams, mussels, crabs, shrimps, and other unwanted organisms. reef rock is much more desirable then inshore rock because it cycles more quickly and stabilizes a tank much faster.

There is also dead base rock, meaning it has no live growth on it. This is rock that is devoid of external life that probably won't see much light, so you can put other forms of more advanced live rock and corals on top of it to build your reef system base, once your tank has settled and the base rock is seeded or cured. Beginning a reef tank using seeded base live rock as the center stones of the aquarium is not a bad idea. Once the base rock is established, then you can begin to add, slowly, more advanced types of live rock.

Some descriptions of live rock sold by suppliers can be confusing. For example, Live Rock supplier describes their Pacific live rock as, "Actually pieces of coral skeletons that have broken off reefs during storms. This 'rubble' washes in toward shore where it is collected in shallow water." So, is this a lighter type of "reef" rock, or heavier type of "inshore" rock?
What Is The Purpose of Live Rock?

Live rock becomes the main biological nitrification base or biological filter of a saltwater aquarium, (that is if you are using it) while at the same time enhances the look of the aquarium and provides shelter for the inhabitants. To better understand what purpose live rock serves in an aquarium,:

"The use of live rock immediately introduces into the aquarium numerous algae, bacteria and small invertebrates all of which contribute to the overall quality of the aquarium water. Live rock has just as much, if not more, surface area for bacteria than a trickle filter. Since live rock in the aquarium contains various types of bacteria, algae and corals, waste products such as ammonia, nitrate and phosphate can have a number of fates. Ammonia, nitrate and phosphate are readily assimilated by algae and photosynthetic corals growing on and in the rock. Ammonia can also be quickly converted into nitrate by the bacteria on and in the rock. This nitrate can be either absorbed by the algae and corals, or it can be denitrified by bacteria in close proximity to the nitrate producing bacteria."

No matter what type of live rock you choose to use, as you may know, a biological filter base base has to cycle and settle for your aquarium to run properly, and this pertains to the curing of live rock as well.

If you are planning on adding it to youraquarium:
Don't overload the system! Even top quality, fully cured live rock can be quickly turned into dead base rock if mass quantities are introduced all at once. It is not a bad idea to add small amounts a little at a time, and test, test, and test again. When the tank settles, wait a little longer and then move on to the next phase of adding a little more, repeating this process until you've obtained the total quantity of live rock desired.


Live rock can and usually does have types of corals growing on it's surface, depending on the live rock.

Your water quality with salt tanks doesn't tell you when the bacteria has matured enough to sustain certain types of marine life.

Also, using 300 pounds of substraight? Your snad and crushed coral should be no deeper than 2" max in any one area of your tank. This causes the build up of bad bacteria for your fish in an enclosed system.

Don't forget your rocks and sand are dieing off and regrowing. Levels could easily spike and return to normal with in a matter of a few hours.

How long have you had your tank running? How did you add your fish to the tank?

It is a bioload/bacteria thing. If you like email or im me and I will help you try to get a hold on what is going on in your aquarium.