Dead Fish Question

[LPMurphy]

I had floater yesterday am and another today. My system is not covered yet and we got hard rain two days ago if that matters. My water was clearer yesterday and even more today. I can see the fish at the bottom of the tank now. You can see those prior pea soup pics at the bottom of
http://www.aquaponicshq.com/forums/showthread.php?p=14412#post14412

Is there anything the condition of this dead fish can tell about the problem (please other than the fact that it is no longer respirating). Is there anything else I can see if I disect it that will tell me?
You can see some redness around the gills, the black spot on the chest and I am not sure if the green just past and below the gills is normal.
I've added white distilled vinegar in 118l increments on the 26th and 27th for Ph - will add another today.
Water Stats
PH - 7.4
Ammonia - <.25
Nitrite - <.5
Nitrate - Between 80-160

[Castaway]

I would go straight to an Aquarium/Pet Shop and buy a good aerator with say a 4 hose outlet, some plastic tubing and some air stones and I would oxygenate that green fish tank you have 24/7. I could be wrong here - but apart from pH concerns, I suspect lack of dissolved oxygen is what killed your fish. A little splashing water from the Grow Bed return pipes may not be enough to oxygenate your fish tank sufficiently and keep those fish alive. The cost of running a 10 watt aerator is minimal costing only cents over the course of a year. If you can also get some current flow from the return pipes say three return pipes angled to create a water swirl effect so the fish have some current flow (imitating nature) to swim against you'll find that they'll perk up a bit. Good Luck but do get some air into your fish tank.

[Murray]

I suspect lack of air and water movement to be the main problem.
As Castaway says, get that water moving and plenty of it. Loads of air going into the system with the tank covered from the sunlight and ingress of rain.

The pH is a bit high, but nothing to worry about....It would not cause the deaths at that level. (due to ammonia toxicity)

[fishfood]

Thay also look skinny like they are not eating [ i bet theres nothing in there belly]

[LPMurphy]

Thank you to all for the input - it is truly appreciated.
Interesting observation Fishfood. I cut one open and no there was not any food in it's belly. If it floated close to the time it died it had been about 20 hours since feeding - not sure if there still would have been food there anyway. However, I had been weary of overfeeding and hand feeding them enough to last till they were through with the frenzy and acted picky (took about 15mins).
I experimented and went back and fed again in a couple of hours to see how they acted and they went at it again. Next night I fed double what I had been and they took it all.
I suspect a combination of both underfeeding and DO - especially considering I am feeding at night where the algae in the water is sucking up the DO at night. They just would not eat during the day when I tried.
I do have my system setup to push 1135l of water from the sump into the 1325l FT every two hours. It takes 13 mins for the pump I am using and I get a lot of movement and spray doing it - probably what has kept me from disaster for now.

[Murray]

setup to push 1135l of water from the sump into the 1325l FT every two hours.At the end of the two hour gap when there is no water movement the DO will be greatly diminished. It does not take long for the oxygen in the water to be used up by the fish. It is better to have water movement all the time or at least in much shorter cycles.
Some fish in any given school of fish, are at the bottom of the pecking-order and just do not get to eat.

[aussieap]

you need the water in your fish tank changing over once every hour to keep DO up, even at non commercial stocking densities.

[GaryD]

.....and I'd suggest that you run a separate air pump anyway. It's cheap insurance.

Gary

[LPMurphy]

you need the water in your fish tank changing over once every hour to keep DO up, even at non commercial stocking densities.

This begs another question. It takes 13mins for my pump to push all the sump into the FT. Have not timed how long it takes to dump all of it into the growbeds - maybe another 10-15 mins- but it takes about an hour to fully drain the beds.
What kind of timing are ya'll doing for flood and drain for the beds?

[Murray]

On my old Homestead kit the cycle was 10 minutes to pump the beds full and 40 minutes for them to drain.
Now that all of our systems are CHOP the cycle is around 12 to 15 minutes.
I notice in high summer the shorter cycled systems did better. There was no wilting between cycles as there was on our really hot 38 to 40 deg days in the old flood and drain 50 minute cycle system.

[LPMurphy]

Are you starting your next cycle immediately or letting the growbeds sit for a period of time?

[organicusrex]

http://www.aquaponics.net.au/Chops.html

This animation may answer some questions for you on how Murray cycles his system. I believe this is the most efficient way of moving nutrient water through a system I've seen thus far.

It involves the use of valves to adjust the timing but that's all explained in his DVD. It's worth the cost.

Cheers mate,
Dean

PS. Push the "Start Pump" button and enjoy.

[LPMurphy]

Thank you, that flow seems to be exactly what I am doing. Unless it is just the animation resetting, it looks like the pump stops for a time. Or is it really constantly running?
The question came up because Aussap had mentioned he would cycle every hour which for me would start a new flood/drain before the growbeds finished draining.
I am all for and already ordered an air pump with a battery backup (I live in the sticks and would cost more to drive to a supply store than get more fish), stones, DO test kit and accessories - the comment just made me wonder if my drain should be faster and how long the beds should have a no-water rest.

[Murray]

It is just the animation re-setting.
The pump runs 24/7
Much smaller and less expensive pump/s can be used in a CHOP system. The fish are always safe. Flood and drain is achieved by the use of auto-siphon devices.
The need for float switches or timers is eliminated.

Float switches and timers bring with them a lot of grief.
Over a period of time, they are very unreliable.

A "no water rest" is not really necessary. In most systems there is an inch or two of water always in the bottom of the grow beds. The cycle time is not all that critical. The bigger the individual beds the longer it takes to fill and empty, so the cycle time is, to a degree, governed by the size of the beds you have. The biggest beds I have in flood and drain systems are 585 ltrs which is about 150 gallons?

[LPMurphy]

The tanks are covered, the water is clearing up, the air pump has been in and running however while the fish die off had subsided it is now ramping up more than ever. I lost 10 yesterday and am on track today for the same. They will not eat - 3 days now.

Several I pulled from the water either at the time of or just after dying had blood around the mouth. Other than that - skin and body looks fine. I hope someone on the board has seen this and has some solid ideas.

Yesterdays 5-12-09 water levels
DO levels at 68f – 8.0 saturation
PH 7.8
Ammonia .5
Nitrite .5
Nitrate 40
Added 2 cups vinegar and 8 tablets of ammonia clear.

Today 5-13-09 – Wed 08:45
Water temp 68 degrees – DO 7 saturation
PH 7.8
Ammonia >.25
Nitrite >.25
Nitrate 20-40
Added one more cup vinegar

[aussieap]

Sounds like ammonia toxicity. I don't understand why you are adding ammonia tablets to clear your tank. It will clear naturally in time and in the mean time the ammonia tablets are harming your fish I think. Google fish ammonia toxicity and have a read.
It is best if our systems are cycled BEFORE we add fish, ie ammonia and nitrite have spiked and dropped to zero. That way the fish are not being stressed during the cycling process.
I could be wrong but my 2 cents.

[LPMurphy]

Aussieap, the input is definitely appreciated. The ammonia clear tablets were for aquarium fish so I am curious why it would hurt the fish. I was just wanting to do something/anything to help their stress.
Lesson learned on cycling first. I thought it had - my ammonia was zero last week - though the nitrites only got as low as >.25.
I was referred to an article that looks like the problem - they have had white spots on their back that I thought was just normal. They were infected when I got them.
http://www.aces.edu/dept/fisheries/aquaculture/documents/EntericSepticemiaofCatfish.pdf
Unfortunately as they are not eating (if the proposed antibiotics would not hurt the plants) using it would not be effective. It looks like all I can do is wait and see how many, if any, survive.
Feels like months of work wasted. Scratch 50 fish today. I will have to search or post to figure out how I can disenfect my system without killing the plants if I lose them all.

[fishfood]

Just wondering have you salted yet 3 kg per 1000 litres will give 3 ppt and most plants will stand that

[aussieap]

+1 for salting. It seems your fish have ich, they should not have been sold to you like that and I would be ringing the supplier asking for replacement fish.

You don't need to disinfect your system. Ich needs a host at one stage in it's life cycle iirc. If all the fish die (hopefully they won't) there will be no host for the next generation.

As a matter of course, you prolly should salt all new fish in a small aquarium or bucket with a bubbler to between 3-5 parts salt, before introducing them to your system. This will help them over the stress of shipping and help knock out some nasties they may be carrying.

I may have misunderstood your comments about ammonia tablets. I thought you had bought some to kick the cycle along when it seems they are a tablet to clear ammonia. Either way, you don't need them, the bacteria in your grow media will handle things in their own time.

It is just as important to hear about the tragedies as the triumphs so thanks for sharing and get back on the horse!

[Outbackozzie]

Them ammonia levels were not cause for concern really...I'd definately say ICH, salt to 3ppt, then cross fingers.

Stop adding vinegar. Let the system stabilise before doing anything else. You'll find the vinegar is dropping the ph right down quickly, stressing the fish. Then your system is buffering it right back up, stressing the fish.

Just let it go. Unless the ammonia or nitrite get above 1, dont mess with it anymore. No tablets or anything else into the water.

If you can, circulate more water through the growbeds.

Good luck

[LPMurphy]

I have bad news - good news - and not sure of everyones reaction news (I used antibiotics).
For those following my plight. Lost all of fish batch #1 - it was a bacterial problem from the hatchery. They replaced the fish with fish that could be argued were sicker. Some had fin rot and some gill.
The salt helped a lot by keeping all stabilized till I could get some antibiotics. Perhaps things would have gotten better but I just did not want to risk losing all again.
I am on day four of amoxicillin (Fish MOX) and made the last 24 hours with no more deaths. One that had a seriously inflamed gill either has not come up to let me get a good look at it or it is really better. There are still a couple fluttering occasionally but anytime I even grab a net they hide in the group. Between the difficulty of isolating the sick ones and figuring the exposure was already high I decided to risk treating the whole system. I am not thrilled I had to go to this decision but.....here we are.
My water levels are great - Ammonia <.25, Nitrite=0 and Nitrate 40. PH is still high 8.2 but I have stopped adding vinegar as suggested. Plants are not showing any issues from all this.
I had a bath setup in a hospital tank with tetracycline and tested one fish - it did not go well. I will go to terramycin if I have to - but am hoping we are past this and can get back to a more natural management system. Of course between the salt and the MOX - my water is not crystal clear again - kind of brackish. I did a ~10% water change today, am planning on that again tomorrow and have water dechlorinating (sitting in a trough) for a 23% in a couple of days.

[Jonty]

Sorry to hear about your fish problems. Aussieap has hit it right on the head about a separate aquarium. I use a 100 litre trough that I fill and salt so I can check for signs of disease before they go in the main tanks.

I have kept saltwater and freshwater fish for over 40 years and the best advice I can offer is to cycle your system, then leave it alone and let mother nature take it's course. My systems run with a pH of 6 - 6.2. The fish will adapt to any pH but dislike rapid pH fluctuations. A ph below 7 gives a wider margin for error if something goes wrong.

Personally, I'd change the fish supplier.