FishProfiles.com Message Forums

I've had fish in the past (in my youth), and I consider myself a somewhat intelligent person... but I can't seem to figure out what's going on with my tank here. Please help me.

I just setup a new 30gallon aquarium. It's a tall, half-circle shape, with LED lights. I installed a heater (appropriately sized) and an AquaClear 50 (for 30-50 gallon aquariums). I'm using pool filter sand as my substrate (which was washed thoroughly) and have two big lace-rocks which I purchased at a local rock store. I scrubbed the rocks thoroughly with a stiff nylon brush and hot water (no soap). I read just about everything there is to read about how to cycle a tank. I filled the tank with water, 5 gallons at a time, all the while treating the water with water conditioner and bacteria supplement. I also added a bacteria in a bottle solution from my LFS. I opted for the 'fish-in' cycling (rather than fishless) and here's what happened...

Under the advice of the folks at my LFS, and everything I read online, I purchased 8 zebra danios to cycle my tank. I fed them only a small pinch of flake food every other day (as advised by my LFS). Over the course of three days, 4 of them died. I used my "API Master Test Kit" every day, each time reading zero ammonia, zero nitrites, and zero nitrates (obviously). My PH is steadily 7.4 and my tank temperature is a steady 76 degrees. (according to two different thermometers located in two separate areas of the tank). The next day another danio died and my levels remained at zero. (My LFS tested the water and confirmed my tests.)

I opted to try a different species of fish, the tiger barb (which is what I'd like to house ultimately). I purchased 6 tiger barbs from my LFS and added them to the aquarium with the 3 remaining danios. 24 hours later, all the barbs were dead. Everything in my tank remained the same, except for the ammonia which climbed to a trace amount: <.25ppm. Another test at my LFS confirmed this as well.

I did a 15% water change, ammonia levels decreased (lesser, but still reading a trace amount somewhere between 0 and 0.25). I purchased 6 more tiger barbs, at a different fish store. I got these ones at petsmart, because they were bigger (seemingly older and perhaps, stronger?). 48 hours later only 1 remains. Ammonia levels now read 0, as well as nitrites and nitrates. PH is unchanged. And to top it all off, these last barbs killed all but one of the danios (and the one remaining seems to have been nipped a few times and doesn't look good).

Also, yesterday, when there were 4 barbs and 2 danios alive, I added some substrate from a friend's established tank.

What am I doing wrong? What am I missing? What should I do next?
With this record, I don't want to keep adding fish. At the moment I'm 2 for 20 in the span of a week. This is sad.

I'm about ready to give up.

UGG sounds frustrating, looks like you did your research, from the results of your water tests and based on the fish you chose to cycle with you are doing the right thing.

First, how well does your LFS take care of its fish? I've sadly purchased from a LFS that had dead in their tanks (was the only option as no other store had the fish we wanted). I knew I shouldn't and sure enough not only did those fish die but they took out some others with them. Any stress your fish are under before you take them home is going to be exacerbated by the trip and the acclimation and may not handle the stress well. Be sure you acclimate slowly. 15 min water temp adjustment in the bag in the tank, then remove the bags and transfer the fish to a tank only bucket, slowly over a few hours time add a little of the water from the tank into the bucket. I usually take an hour minimum, closer to two or three. Then net the fish out and place them in the tank. Dump the water from the LFS and your tank that is now mixed with the LFS water in the garden. Be sure to use dechlor if you top up the tank.

Secondly, have you tried adding Cycle or Biospira to the tank? It's bottled bacteria you can get from your LFS and should help cycle the tank.

Third, did you rinse out the tank before filling it if it was new or in storage for a while? They can sometimes get contaminated.

^_^

Thank you for taking the time to reply.

I've attached a photo of my tank, in case theres anything that jumps out visually. (And no, the cat isn't what's killing the fish!)

My LFS is supposedly a very well renowned store. It's well reviewed online and my friend who keeps fish swears by them. They were also recommended by someone at petsmart (telling me I should get my fish from there if I'm having problems, then I explained that I did, and round we went). The fish looked healthy. The barbs especially were very active and inquisitive about every nook in the rocks, etc. The barbs ate well (so did the danios, but the barbs seemed to enjoy it more). They schooled (when there were enough of them, that is) and battled a little for dominance, everything seemed right. Until the morning when they were all dead.

Consensus on another forum seems to think that my large lace rocks were the problem because of possible contamination. I purchased them from a rock yard and they were housed outdoors. But as I said, I scrubbed them pretty good (I think?).

Right now I have 2 fish alive, one tiger barb and one danio, but the danio is on his way out (because of the barbs, the danio has not much tail fin left unfortunately). The fact that a couple fish have survived leads me to believe that my tank isn't toxic.

What I'm going to try is this:
My rocks are too big to boil, so I'm going to put them in the dishwasher, with no soap, high heat, run it a couple of times, and then let them soak in a bucket or something. Then I'll return them to the tank.
And while that's going, I'm going to do a large water change (75%).

If these two fish survive all of this, and last the weekend, I'll try adding some more barbs.

Otherwise... I'm really at a loss. I could try the fishless cycle, but I'm not convinced that the cycling is what's killing these fish (afterall, the ammonia was only a trace amount and not for very long... aren't these fish supposed to be tougher than that; isn't that why they're the species everyone recommends for cycling?).

Attached Image:

Cat's in the box, always the way with cats. "ooo a box, must sit in it"

anyway.

If they were that active I doubt their previous health was the cause.

Did you test the rocks before putting them in to make sure they don't leech into the tank and raise the PH? With the fish you chose I wouldn't guess that's the reason, but it's always better to check.

Since you did do the scrubdown you probably removed as many contaminants as you could, however if it was stored outside it could have been sprayed with who knows what that isn't easily removed. Anything from pesticides to gasoline contamination. You'll know the area better than me of course so in your good judgement you could decide if it's worth it to keep the rock in the tank.

Don't add more fish till the tanks fully cycled, adding fish mid cycle can be really bad. The fish in the tank are already used to the higher ammonia levels, you need to continue to let that build then fall as nitrIte takes over, and again till the nitrAtes are present in the tank and ammonia and nitrIte is zero. If you need more info on the nitrogen cycle there's a good article listed at the top of the site under the FAQ's.
Look at getting some bottled bacteria (I'm a fan of Cycle mainly since it's a bit cheaper). If your last fish do die, I'd still suggest getting the cycle, and using the fishfood to act as the ammonia source till the tank is cycled. Basically feed the tank a sprinkle of fish food every day, it breaks down to cause the ammonia and nitrIte spike, you'll be able to track it by using your test kit daily, then once you're cycled you can slowly start adding fish.

You didn't say, and I hate to state the obvious, but did you use dechlor when you added the water to the tank?

Also, I see an aquarium salt box in the background? You're not adding any are you?

My other thought is that since it is a tall (remember that will reduce how much you can stock in the tank) there's not quite enough surface agitation and therefore reduced oxygen levels. You could try adding an airstone to increase surface area, or lower the water level a bit more to create more splash from the AC outflow. The fish may not be obviously gasping at the surface (a sure sign of low oxygen levels) but low activity can also be a good sign. Since the ammonia in the cycling process reduces oxygen levels it could be a factor in their deaths.

^_^

I'm not sure how to test the rocks?

I did add salt... as a last resort under the advice of someone at the LFS.

I added one tablespoon.
The dosage says to use 1tbsp per 10gallons as a "tonic" for the fish.
It's hard to say whether or not it did anything since I added it only recently (yesterday, when 4 of the last batch of barbs were alive), and didn't add much anyway.

And I did use a water conditioner and have with subsequent water changes.

I have an airstone, I'll turn it on. I just haven't set it up yet because I started to encounter these problems and was told that the airstones are mainly aesthetic (so I didn't bother yet). I'll give it a shot though. I did notice a couple of the barbs, as they were on their way out, swimming near the top sort of gasping at the surface. But, this was only as they were dying, not something that they did all along. Perhaps it was foolish of me to overlook this as a possible sign of a lack of oxygen. Aside from the air stones (I'll add a couple) what else can I do for this?

Hi, and Welcome to Fish Profiles!
Wow, that's quite a litany of problems.

Because you do have fish living in the tank now, although
just a couple, I do not think it is the rocks that are the
problem. Any contaminates (chemicals) on the rocks
would have killed all of the fish.

Just a couple of comments on the bottom of the
tank, from the look, and your comments, the rocks are
carbonates, and over time will raise your pH toward an 8.
The pool sand is a silica (quartz) and is inert but
fine. You should keep the thickness of the substrate to
an inch or less. Otherwise you can wind up with dead
areas of anaerobic bacteria that generate toxic hydrogen sulfide (a rotten egg smell).

Another future "problem" that may come about is an outbreak
of "brown algae" which is actually a diatom bloom. The
diatoms (always present) require silica to live (forms
their skeletons) and the quartz pool sand is chuck full of
it.
Some fish love the stuff and will eat it.
Frequent water changes, good circulation, and adequate
light will discourage the bloom and it will eventually go
away.

Because it is a "tall" tank, you have to be concerned about
circulation within the tank. The filter intake is down
into the bottom half of the tank which is good. If you can
get an extension piece of plastic to take it down even
further leaving the intake about two inches above the
substrate, that would be better. I would set up the air
stone, to encourage even more of a turnover within the
tank and eliminate any "dead" zones or sumps, where
detritus would accumulate.

From the perspective of the picture the tank would seem
to be on the the floor, be careful when you put the
tank in its final position that the rocks don't shift
and scratch the tank.

Using salt in a tank should depend upon the fish that you
are keeping and not be just a general additive. Remember
that salt never evaporates with the water, instead,
it becomes more concentrated. Never add salt with your "top off" water. If you do, you will eventually
turn the tank into a brackish water tank and kill off
your freshwater fish. Salt tends to stress (change) the
metabolism of a freshwater fish causing it to secrete more
mucus and in others causes a more intense coloration.
It really is not a cure all.

Unless you are using well water from your
own well, the tap water will contain chlorine and probably
chloramine which is a compound of chlorine and ammonia.
The only way to neutralize it is with a water conditioner
that specifically states that it will do that. When the
conditioner neutralizes the chloramine, it changes the
ammonia to a non toxic form. Your ammonia test, however,
will read it as ammonia and give you a "false" reading.
With the .25 reading of ammonia, I think that is what you
are reading and interpreting as a waste product from the
fish, when it is actually just the normal reading from the
conditioned tap water.

I'd continue to feed the remaining fishes and do regular
water changes. I also would encourage you to use
the bacteria products that Babelfish is recommending,
to help cycle your tank. The two or so fish that you
have in that 30G tank will take quite a while to
provide enough waste to cycle the tank by themselves.

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

So far so good!
Thanks for the help everyone, I really appreciate it.

Under the advice of you folks and some help from another fish forum, I determined that the problem seemed to be oxygenation.

[I installed two air stones and...] I moved my air-stones around a little and found that the best place seems to be putting them in the corners of the tank (It's a half-moon shape, like a "D" and putting them in each of the two corners seems to disrupt the surface the most, also helps to circulate the water more than placing them else ware).

I've got 4 barbs in there now and they all seem OK, going on 72 hours now. One is a lot more active than others but I think that's a dominance issue not a health matter... he's also the biggest and most colorful.

I've been monitoring my ammonia levels and doing small water changes to keep them in check. Also I switched to PRIME instead of the store brand water conditioner I was using. Again... so far so good!

Thank you again.

Congratulations!
Glad we could help. Have Fun

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

I don't see anyone mentioning acclimating the fish. How are you acclimating them before putting them in the tank?

I used to have large numbers of fish die within a day or two when I only acclimated them for an hour or so. Since I started doing it for more like 4 hours(Or more) I haven't had a single one die. I just float them in the tank and put a cup of water into the bag every 15 minutes.