Random Dead Fish

[Jeremiah Robinson]

Hi there,

I've got some tilapia fry who died recently, for no clear cause.  They system is stable at just about every level right now, for the past few days.  So I'm just kind-of wondering: other than ammonia/nitrites, what are the top reasons fish die with no obvious cause?

For my fish specifically, I've put them through some mild pH changes and not-so-mild temperature changes over the last couple of weeks.  I have some food made myself from the following recipe from RD Aquafarms.  They ate it excitedly when it was fresh, but since I've frozen and thawed it they seem less enthusiastic.

• Soften 1 quart of dry fish food in water
• Mix 2 eggs into food
• Boil 2 cups of water and add 1 ounce of Knox gelatin, sir until disolved
• Mix gelatin with egg/food mixture, an old food processor or blender works well
• Recipe can be cut in half. Store in refrigerator!

[Harold Sukhbir]

Hi Jeremiah,

" what are the top reasons fish die with no obvious cause?"

One Answer is

" not-so-mild temperature changes over the last couple of weeks"

Also you will need to give a history/background of your system, water test etc. leading up to the fish deaths.

[Jeremiah Robinson]

Hi Harold,

That's good to know, that temperature swings can kill fish even days after they occur.  I've only lost a couple of fish out of a hundred, so I'm not really that concerned.  The issues I'm aware of are resolved or soon to be.  More curious, and interested in knowing if there's a triage list of most likely causes of death in general.

Here's a brief history of my fish:

• April 10 - Fish arrive, put in small tank in kitchen as larger tank in greenhouse stabilizes.  Everything stable, fish eating and living happily.  Temp. 78 degF
• April 18 - Algae bloom sucks up oxygen, causes fish to sip from top of tank, forces me to move them to outdoor tank with Nitrite levels at 3 ppm.  None die.  Levels stabilize to zero within 24 hours.  Temp 75 degF.
• April 20 - Notice some mold on the top of the food, throw out top layer, freeze the rest.  Start thawing and feeding 3-day supply at a time.  Fish don't eat the thawed food very enthusiastically, but do eat it eventually.
• April 24 - Problem with controller causes temperature to spike to 93 degF overnight.  Lowers slowly back to 75 over about 36 hours.
• April 27 - Greenhouse getting hot.  Experimenting with heater.  Water hits 80 degF a couple of times.
• April 28 - Left aerator off overnight.  No obvious ill effects.  Back on in morning.
• Apr. 30 - One dead fry
• May 2 - Two dead fry

[Harold Sukhbir]

Hi Jeremiah,

Ok so I see you're very knowledgeable/experienced with AP. Jeeze...with what your system has been through I'm surprised there was so little in the way of fish deaths! I don't recall seeing a comprehensive list on the forums on possible causes/conditions leading to possibilities for fish death, so may be you can start one here. Its an interesting topic for sure!

A separate topic heading(List of possible causes of Fish Death) will attract more response to the topic?

[Gregory J. Showalter]

Hi Harold! I so much appreciate  your comments. Would this be my problem too? May 31st I added channel catfish. June 2nd I found two dead floating and this morning the 3rd two more. (put in 25 to my 3,000 gal pond/tank minimum purchase) 0 ammonia and nitrites. PH rose a little, @ 7.4-7.6 for some reason I get rain runoff into my pond if it comes down hard. where i purchased them was no doubt a perfect 6.8-7.0., My nitrates dropped to almost zero i think because of the cooling temp. we were getting, was around 5 ppm, i was not quite cycled but felt the temps would start to increase and I needed to get the fish in because of an up coming  unplanned trip and did not want my helper responsible for testing and adjusting water...just to feed fish would be enough for a task. The seller in general conversation about which fish was best for my system said about the catfish that they don't like more than a 10 degree temp. swing for raising. the sealed plastic bag with water and oxygen and fish...the water was COLD compared  to my @69-70 degree pond water. I put the bag in my pond for a half hour before I released the fish. Your comments?

Harold Sukhbir said:

Hi Jeremiah,

" what are the top reasons fish die with no obvious cause?"

One Answer is

" not-so-mild temperature changes over the last couple of weeks"

Also you will need to give a history/background of your system, water test etc. leading up to the fish deaths.

[Harold Sukhbir]

Hi Gregory,

Fry experience shock during transport.

Packaging/oxygen levels in container and those in FT.

Temperature differences in container and FT

Differences in PH between container and FT.

These are some obvious reasons for fish deaths. The size of the fingerlings, the conditions of where they were kept, how we acclimatize the fry to the FT is also very important. Punching a small hole in the transport bag to slowly mix PH and temperatures etc. Fish that are affected continue to die sometimes over a long period of time due to the shock/damage they experience during placement.

From the length of time and your water test I don't think that anything in your AP is causing any problems.Everything should settle down and the deaths stop. Please post about the situation If you continue to lose any more fish. In the meantime do some daily test and record the results.

[Gregory J. Showalter]

Harold, I noticed something that took my breath away after watering my conventional garden that surrounds my Greenhouse/AP setup. I discovered the very place that rain water and also my chlorinated  garden hose water I use to water my conventional garden is ENTERING MY AP pond (after I watered my conventional garden today!) I'm heart broken. It just trickles in from garden watering and with a rain down pour like we had the last few days it raised my 10X17X4 deep pond by 5 or more inches! is the trickling in from the garden watering (chlorine) enough to cause fish loss? I now have the problem of changing PH after a hard rain. I obviously have a low spot, low enough to alow the outside water to enter. I think it would be to big of a project to try and dig up and raise or block up the low spot unless I tear apart the green house in that area and do some major excavation. I probably could spot water the plants in that area to reduce run off and also use as much rain water in my rain barrels to elminate any chlorine!!??? seems like the challenges never end!

Harold Sukhbir said:

Hi Gregory,

Fry experience shock during transport.

Packaging/oxygen levels in container and those in FT.

Temperature differences in container and FT

Differences in PH between container and FT.

These are some obvious reasons for fish deaths. The size of the fingerlings, the conditions of where they were kept, how we acclimatize the fry to the FT is also very important. Punching a small hole in the transport bag to slowly mix PH and temperatures etc. Fish that are affected continue to die sometimes over a long period of time due to the shock/damage they experience during placement.

From the length of time and your water test I don't think that anything in your AP is causing any problems.Everything should settle down and the deaths stop. Please post about the situation If you continue to lose any more fish. In the meantime do some daily test and record the results.

[Alex Veidel]

I don't think you should be using chlorinated water to hydrate your conventional garden. There are plenty of beneficial bacteria in a soil garden that would do better not being killed :) Attach a dechlorinator to your hose.

Gregory J. Showalter said:

Harold, I noticed something that took my breath away after watering my conventional garden that surrounds my Greenhouse/AP setup. I discovered the very place that rain water and also my chlorinated  garden hose water I use to water my conventional garden is ENTERING MY AP pond (after I watered my conventional garden today!) I'm heart broken. It just trickles in from garden watering and with a rain down pour like we had the last few days it raised my 10X17X4 deep pond by 5 or more inches! is the trickling in from the garden watering (chlorine) enough to cause fish loss? I now have the problem of changing PH after a hard rain. I obviously have a low spot, low enough to alow the outside water to enter. I think it would be to big of a project to try and dig up and raise or block up the low spot unless I tear apart the green house in that area and do some major excavation. I probably could spot water the plants in that area to reduce run off and also use as much rain water in my rain barrels to elminate any chlorine!!??? seems like the challenges never end!

[Harold Sukhbir]

Hi Gregory,

I have a friend with an in-ground FT who experienced the same, but his comes from a nearby river when it becomes flooded. He put in a concrete filled trench and on top of this, a one row height of concrete blocks all around the FT, which solved his problem. Your guess about the fish deaths and this occurrence is a plausible enough assumption. Dealing with rainwater affecting the PH is not such a big problem and should not be the cause of fish death. Chlorine could be entering the FT and you could do as Alex suggested as a temporary fix. Notice a bucket under a dripping faucet overnight and you'll get an idea of the effect of the trickle y6ou're getting now. Unfortunately in AP we learn more from our mistakes than anything else

[Gregory J. Showalter]

Alex Veidel said:

I don't think you should be using chlorinated water to hydrate your conventional garden. There are plenty of beneficial bacteria in a soil garden that would do better not being killed Attach a dechlorinator to your hose.

Gregory J. Showalter said:

Harold, I noticed something that took my breath away after watering my conventional garden that surrounds my Greenhouse/AP setup. I discovered the very place that rain water and also my chlorinated  garden hose water I use to water my conventional garden is ENTERING MY AP pond (after I watered my conventional garden today!) I'm heart broken. It just trickles in from garden watering and with a rain down pour like we had the last few days it raised my 10X17X4 deep pond by 5 or more inches! is the trickling in from the garden watering (chlorine) enough to cause fish loss? I now have the problem of changing PH after a hard rain. I obviously have a low spot, low enough to alow the outside water to enter. I think it would be to big of a project to try and dig up and raise or block up the low spot unless I tear apart the green house in that area and do some major excavation. I probably could spot water the plants in that area to reduce run off and also use as much rain water in my rain barrels to elminate any chlorine!!??? seems like the challenges never end!

[Gregory J. Showalter]

Alex I feel a little embarrassed. Just NEVER thought of a dechlorinator on my garden hose. I've never seen one. Can you recommend? I jumped right on. Your Uncle Jim's worms suggestion!

[Gregory J. Showalter]

I got to thinking Harold, if I dig down three or four feet (a spade's width) around the entire green house perimeter and install simple sock covered house drain tile and empty it to a chosen low spot away from the pond...it should solve my problem. Thoughts?

Harold Sukhbir said:

Hi Gregory,

I have a friend with an in-ground FT who experienced the same, but his comes from a nearby river when it becomes flooded. He put in a concrete filled trench and on top of this, a one row height of concrete blocks all around the FT, which solved his problem. Your guess about the fish deaths and this occurrence is a plausible enough assumption. Dealing with rainwater affecting the PH is not such a big problem and should not be the cause of fish death. Chlorine could be entering the FT and you could do as Alex suggested as a temporary fix. Notice a bucket under a dripping faucet overnight and you'll get an idea of the effect of the trickle y6ou're getting now. Unfortunately in AP we learn more from our mistakes than anything else

[Harold Sukhbir]

Hi Gregory,

Exactly what my friend did to solve his problem except he dug about 18 inches only. It would be better to have more control on the water source/level for the FT.