Expert: Richard Hight - 10/14/2009

Question
Richard~

I have a 55 gallon freshwater tank with 2 Fantail Goldfish, 2 Black Moors, 7 Neon Tetras, & a Common Plecos.  I am a fairly new fish owner and as a result, I initially started with a 10 gallon tank that was much too small for my Goldfish & my Algae Eater, which were the only fish I had at that time.  I upgraded about three weeks ago to the 55 gallon and added the Neon Tetras shortly thereafter.  I used Biozyme for the first week and a half, to jumpstart the growth of good bacteria.  I have read about new tank syndrome and had faith that this product would do what it claims to do.  I had great luck with the new tank (which also has a filter with carbon in it) until yesterday.  My Algae Eater died and I have no idea why.  He went to a dark place in the bottom of the aquarium yesterday morning, stayed there all day and then, by evening, had died there.  

I have not rinsed the brown permanent filter that sits back-to-back with my disposable filter, because I know that I needed to establish the growth of beneficial bacteria.  All of my other fish are thriving in the bigger tank.  I haven't seen any sign of illness in any of them.  I've tested the water with a five-in-one test strip that measures Nitrites, Nitrates, Alkalinity, pH, & Hardness.  The water registers to be ideal in all of those categories.  I used water conditioner when I initially set-up the tank.  I had been giving him little algae wafers especially for a Plecos before turning off the lights at night, but I'm not sure that he was always the one that ate them--I've seen the Goldfish picking at them before.  I put salt for freshwater aquariums in the tank when I set it up.  The water temperature fluctuates between 73 & 74.5 degrees.  

I can't think of anything else you may need to know to come to a conclusion about his cause of death.  I am afraid for my other fish now.  Do you think I have new tank syndrome?  If so, how can I remedy this fast?  Is it possible that my plecos was simply ill?  I didn't notice lethargy, but then again I didn't expect him to be too terribly active in the day, knowing that he was nocturnal.    I really appreciate your time and expertise in figuring out what happened and helping my other little guys continue to thrive.  

Thanks!
Joy  

Answer
Hi Joy

I'm sorry about your Pleco. There are a few problems here that I'm going to help you correct.

First, what killed your Pleco is the salt you added to the tank. Not commonly realized, but Plecos are a breed of catfish actually. Even the slightest amount of salt will kill scaleless fish. Also, should you ever need to treat your tank for illness, this is also true of fish medications that contain copper. Copper is fatal to both scaleless fish and crustaceans. (shrimp, snails etc)

If you wish to get another Pleco, you'll need to do enough weekly water changes to clear the tank of salt, then replace your carbon filter cartridges. With 25% weekly water changes, your tank should be safe for another Pleco in about 4 weeks. You definitely don't want to change too much water at one time while your tank is still cycling. Make sure you treat the new water with a good water conditioner. StressCoat and AquaSafe are the best choices.

Next, Goldfish should not be living with Tropical Fish. Goldfish are cold water fish, Tropical Fish are warm water fish. This brings me to the next problem...the temperature of your tank is too cool for Tropical Fish, especially the Neons. Water temp needs to be 77°-78°.

Another thing to point out is the Goldfish could eat the Neons at any given time. Neons should be kept with other peaceful, Tropical Fish of similar size.

Finally, I'm not a fan of using bacteria additives. All of these products claim great results, but few actually work. Many aggressive Cichlid owners, especially African Cichlid owners use these products because all of the fish need to be added to the tank at once to minimize aggression.

The best thing to do at this point is to put the Goldfish in a separate tank that is large enough for them, or put the Neons in the 10 gallon with a small heater. The 10 gallon is the perfect size for 7 Neons, but you won't be able to put anyone else in there with them or you will overcrowd them. Whichever you decide, you don't want to add any more fish to the 55 gallon until it is finished cycling, probably in another 2-4 weeks.

I hope this helps you, good luck!

Richard