no fish allowed?

fishy1 · 11-29-2006, 12:13 AM

Thank you for reading my post/cry for help.

My current problem is that I am unable to add any fish to my marine tank. The last three attempts have all ended in death within 24 hours. Within a couple of hours the fish begin to show signs of stress. Mostly it looks like they don't know where to go to escape. Then there is rapid breathing. The tank does have many hermit crabs and other invertebrates. There are no other fish in the tank.

These additions have been attempted over the last nine months or so. The most recent attempt, a blenny, was the first attempt in about six months to add a fish. It was coming from a friend's established tank where it has spent the last year in mostly good health. He did not want it any longer due to a mouth deformity. It seemed a good opportunity to "test the waters."

The tank is a 40 gallon, breeder dimensions. It has live rock and substrate (aragonite) that is about 8 years (or more) old. There is a pseudo plenum system in place. There is a protein skimmer. There are two pumps and spray bars moving the water. Specific gravity is about 1.022. I confess that I have not tested for any forms of nitrogen. The crabs are a recent addition, so no food has gone into the system for those six months. I don't expect there to be any measurable nitrogen. And the fish's small mass relative to the time it was in the tank would not suggest a spike in ammonia.

In preparation to trying to add the most recent new fish I did take a few steps. A good deal of algae was covering the substrate and glass. This was stirred and mechanically removed with a micron sleeve. The sleeve was rinsed several times over a day. Then a 10 gallon water change was done. The tank was allowed to run for several days. I did fear the possibility of hydrogen sulfide being released from the gravel based on my two previous failures. So I let it run not knowing how to confirm or deny the possibility but hoping it would gas out. I also added a bit of chemical filtration (a poly filter, which turned slightly brown).

I'm not sure what to attempt next. The tank, at one time (1997-2004), was rather successful. So, I am reluctant to scrap it and start over. But do I need to? How do I know if the substrate/plenum is the problem? Any suggestions are welcome. Thanks.

**leebca** · 11-29-2006, 04:59 AM

WELCOME TO REEFLAND!
Thanks for posting!

Your 'train of thoughts' and 'logic' to what could be the problems are very sound. But as sound as that is, you are trying to figure out the problem(s) without performing tests. This isn't going to work. Chemical data is needed on the water quality. Since you've presented some concerns and described having a plenum of sorts, you want test kits or measuring devices (no dip sticks) to tell you the following information about the water:
ammonia
nitrite
nitrate
phosphate
Calcium
Alkalinity
Magnesium
pH
temperature
sulfides (for hydrogen sulfides)

I doubt there would be a heavy metal contaminant involved since you have some crabs (assuming they aren't dying either). Still, I wouldn't discount this as yet.

With the above data collected, we can see if there are any concerns there and begin to eliminate what's causing the fish loss.

It will be a process of elimination to get at the problem and it will require data -- test results using accurate test kits and analysis.

That's the chemistry. Now to the identification of the biologics. . .
You mention "algae." That term is used to describe hundreds of different organisms found in marine aquariums, many of which are not algae at all. So, I would want to know exactly what it is you find coating your tank -- color, size, etc. along with the lighting you are using (kinds, hours/day, etc.). Then, I'd like to know about other life in the aquarium. Do you see pods, worms, or any micro-fauna?

What are the crabs currently eating? What are you putting into the tank? What are all the 'other invertebrates' that you say are now in the tank?

You mention the age of the live rock and substrate as being 8 years. Does the 8 go with both the live rock and the substrate? Tell me more about it. Where did they both come from? Did you have them both for 8 years or get it from some source that said they had it that long? From what you wrote I didn't want to assume anything on this subject, but I am guessing you've had them both yourself that long. In this case, I would go ahead and replace the live rock. Keep the substrate.

A browning Poly Filter indicates organics (the manufacturer's generalization). Are you sure the protein skimmer is working properly? Describe the skimmate (the stuff it removes). What does it smell like?

Regarding the plenum, they can 'go south' as apparently you are aware. The sulfide test will show the possibility of hydrogen sulfide. The fix here may be the need to breakdown the plenum and start it again (if it you intend to continue using it). The breakdown process will show up problems in this area.

It's hard to find the cause(s) from your description and doubly hard to find the problems without test data. So I would begin to solve the problem by the gathering of much more information.

BUT. . .

It's an old 40 gallon aquarium. The live rock should need replacing. There are no fish to be worried/concerned about. If it were mine, I would just start over and scrap the plenum, setting up a slightly different but new system.

But. . .get the basic test kits!

***Reefland*** · 11-29-2006, 12:05 PM

Hi fish1,

Quote:

Originally Posted by leebca

It's an old 40 gallon aquarium. The live rock should need replacing. There are no fish to be worried/concerned about. If it were mine, I would just start over and scrap the plenum, setting up a slightly different but new system.

But. . .get the basic test kits!

I couldn't agree with this more. I would perform water tests on the current system, just out of curiousity, and regardless of the results probably start over again. Take the time to upgrade some equipment and intriduce new liverock into the system.

fishy1 · 12-03-2006, 02:42 AM

Thanks for your (quick) replies. I'm not in a big hurry here. But, I would like to solve the problem. If I've been without fish in this tank for a year; a few more weeks won't hurt!

I had pretty much assumed there would be a request for water data. Its been a long time since I've tested the water. Most of my kits have been in the drawer for just as long. And they are liquid reagents on top of that. So, I am not so sure of the results they would produce. Further I don't have much outside of the basics - forms of nitrogen, pH, GH, KH, and phosphate. The closest store that would be able to test or sell me some new kits is a good hour drive away. I may go for a visit tomorrow. I didn't even know that you could get a test for sulfides. A quick internet search revealed that there are some that are based on dip sticks. You cautioned against this. Any suggestions for a brand of sufide test kit?

The rock and substrate have been together, with me for the last 8 years. Their sources vary . . I think some was Tonga. They did go from another tank to this one about 4? years ago. They were in a 30 gallon extra high (24x12 base) with a very deep substate. This tank offered more surface area (36x18) but the substate got spead a little more thin. This tank has never been as successful as that smaller one was. That tank was deep enough to also incorporate a tall internal counter current sanders skimmer. It was old fashioned but it worked! With this tank I put to use an external Red Sea skimmer (prism) someone had given me. I was not a big believer in the skimmer, but it was free and more convenient than the old one. Its product is dark green to black in color. Surprisingly, it doesn't smell as bad as other skimmer cups I have sampled over the years. It is a battle to keep its flow low enough that it doesn't flood its collection cup.

I don't have a clue about the species of algae. So, I'll do my best to describe it. I do believe it was on its last legs, as I had not provided much nutrient to the tank in the last few months. it was not firmly attached. It was on the rocks and covering portions of the substrate. It could be stirred loose and then removed. It has not come back. It was fuzzy/furry in appearance. On the substrate it was darker in color. On the rocks it varied from a light to dark green. It was likely to be many species living as a community! Lighting consists of about 60 watts of conventional florescent tubes (actinic) and due for replacing (yes this is an older, neglected system). And an all-glass 36" power compact fixture that has, I believe, 55 watts of light.

Speaking of not providing much nutrients, there were not many creatures (invertebrates) either. An arrow crab for a time (now in another tank), a couple species of hermit crab (blue legged, scarlet reef), a good number of mullosks that reproduce on the glass - they look like small limpet shells? an emerald crab . . . now that you've asked, I don't recall seeing any other creatures in the substate as there once were, no worms or anything crawling in there. So, your point about the microfauna is well received. My only feeding, in an attempt to starve the algae, was an occasional (once or twice a week) sprinkle of flake food.

You've got me considering my next step will be to remove the plenum system and get more live rock. I don't mind losing the substrate. I'm curious why you've suggested getting rid of the current rock. While it may not be the most interesting at this point, it still provides a good base and is of the right composition. Could you tell me more? I'm gathering from your responses that plenum systems have fallen out of favor. Its been a while since I've paid much attention to the trends in marine aquariums. Now, that I am focusing on this tank rather that the many others, it is like having a new hobby! I should mention, that when I was a more conscientius marine aquarist the plenum seemed to work very well with minimal effort. What are the current thoughts regarding the bottom areas of a reef tank? Have we gone back to the bare bottom/minimum substrate ideas of the 80's? Did that mud stuff ever catch on?

I'll post more once I have some water data. I mostly wanted to thank you for the feedback and let you know I'm still considering all you've given me to think about.

**leebca** · 12-03-2006, 09:47 AM

Good to hear from you again. So many times people post once and then. . .nothing!

Quote: