White Nile Tilapia all died

[Michael Sasarak]

Hello, 

I had White Nile Tilapia in my stock tank (150 gallon). I noticed a few of the fish started to die off and they stopped eating. The water tested good and then I noticed a spike in the ammonia level most likely from the food due to them not eating. I removed the food, did a 20% water change of the course of every 2 days for about a week and a half until the ammonia levels dissipated. 

I noticed that the tilapia that were dying started looking pink around the mouth, gills, fins and the eyes were bloodshot. I cannot for the life of me figure out why and what caused them all to die. I tried saving the last 7 fish by doing a quick salt water bath in hopes that would kill possibly any bacteria that was on them. 

The water temperature was up pretty high almost 89 degrees at one point. I might have slid the dial for the temperature with my foot or perhaps my son turned it, but I normally keep it around 74 degrees. 

Since the fish all died. I drained the water and washed and scrubbed the stock tank with soap and bleach and thoroughly rinsed it. 

I did find a symptoms the fish had similar to a disease streptococcus, which is strep throat and apparently fish can get strep throat too? 

Does anybody have any ideas, remedies, solutions so this doesn't happen again? 

What should I do to my tank now to prevent streptococcus developing again since I filled it with fresh water and am cycling the system for another 6 weeks before I order more Tilapia? 

I thought I had pictures of some of the fish that died, but cannot find them. 

Thanks,

Mike

[Keith Rowan]

with an ammonia spike, you stressed your fish, the ammonia spike was probably followed by a nitrite spike, which further stressed the fish and exposed them to brown blood disease.. what were your other water parameter readings? temp and ph play a role in just how toxic ammonia can be.. a "quick salt bath" might help a little but a longer term salting would have probably been more appropriate (1ppt for a few weeks)

how many fish did you have? how much growbed? (filtration)

 

[Michael Sasarak]

Hi Keith, 

There was an ammonia spike which was reading 2ppm (I believe - I don't have my notes in front of me, may have been .2ppm), but did not catch a nitrite spike in the system when tested. I did at one point have the water up to 90 degrees, but I had it set to 76 degrees which is where I had it since I started the tank. I moved the dial for the temperature control which was plugged in near the floor where foot traffic passes, so either I may have moved the dial with my foot or perhaps my son was playing with it. 

I have 150 gallon rubbermaid stock tank and had about 23 Tilapia in there and a 12 cubic foot grow bed (clay media with red worms) with 4 towers 3' tall each for strawberrys, herbs, and spinach/lettuce. 

[Keith Rowan]

so 9 cubic feet of media is close to 100 gallons (of media).. are your towers filled with media or just "pockets" of media?

with what you are describing, i'd have 20 to 25 fish at the most.. how many did you have?

[Michael Sasarak]

Keith, 

The towers are constructed of PVC fence post (square) and the pockets are circular PVC drain pipe cut at 45 degrees. I then filled 3" netting pots with the media in order to stabilize the plant. I had 23 Tilapia in the tank. 

[Keith Rowan]

so you weren't overstocked.. missed your comment about the number of fish..

since you bleached the system it's going to take a while to cycle up..

salt before adding the fish (to 1ppt)

i give a 35ppt salt dip to fish before introducing them into the system

[Michael Sasarak]

I will salt, but wont the salt be a problem to the plants I have in my system already?