Krantz

Trouts dying. pH ok. EC Ok. Food Ok. I don´t know what else to do.

37 posts in this topic

Hi all

 

I would like to seek for your advise on this topic.

 

About a year ago I set up an aquaponic farm; I have two independent systems (let's call them system #1 and system #2) under the same greenhouse; each system has 2 IBCs as fishtanks, 15 square meters for growbeds, and 5 square meters for floating raft.

 

Each has two IBCs as sump tanks.

 

I started with Tilapias - big mistake because of temp- during winter I spent thousands trying to keep water at a decent temp.

 

On jan, I gave them all away, cost was crazy.

 

Then I got trouts (240 fingerlings, 60 for each IBC).

 

They were doing great at first, but one day, around 100 of them died suddenly, all from system #1: My immediate thought? oxygen -- so besides the 4 air pumps I already had for both systems, I got 4 additional 60LPM pumps and 8" airstones, and put one for each fishtank.

 

On march, 10 more died out of the sudden, no reason -- system #1 again.

 

On april, 2 or 3 more died, so I got tired and started checking up system #1, I took all the fish out from that system and put them in a separate, 300 liter tank with fresh water; I do water changes every 5 days -- water is sometimes soo dirty I cannot see the trouts -- but nothing happens to them -- happy and eating.

 

Yesterday, I decided to take around 100 liters of water from system #1, and mix them with other 200 liters of fresh water, so the remaining fish could start to acclimate to their original system --- today, 2 of them dead.

pH: 6.5 on system #2, 6 on system #1

Nitrites: very low on both systems

Nitrates: around 20 - 50 on both systems

Ammonia: 0.6 on both systems

Water temp: oscilating between 15 - 17 C daily.

EC: 0.351 on system #1, 0.353 on system #2
ppm: around 200 each system.

 

I did a complete change of water for system #1at the end of march.

Plants in system #2 are beautiful, but in system #1 are very small, they look sad.

I just don´t understand why the fish suddenly die, during night. I´ve cracked my head for months now, and I cannot seem to find the answer; also plants are not growing as they should.

 

Is it possible that some plants affect the water or the fish in some way? I ask you this because in one of the grow beds I have some very nice little plants, like water lilies, except they grow on soil; Also I keep a very small plant of levomenthol - I keep them because my mother likes them and uses them - but I am starting to think maybe some plants are affecting the chemistry in some way.

 

Is there anything you can think of?

 

 

Thanks in advance.

 

 

 

 

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Hard to pin point the issue with the info you have/gave. As you probably know yourself; fish dying like this is most likely a result of something toxic in the water not a disease.

 

Couple of questions:

 

What is your water source?

 

What do you mean with ppm in waterquality results? salt??

 

Anything made from metal in your system? (other than stainless steel). I have seen rainbow trout dying from water collected on a zinc roof with galvenized gutter.

 

Do you use soft pvc hoses in your system? (might leach plastizer)

 

Did you use bathroom silicon? (potential anti-mould agents)

 

Stray voltage on the water?

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I recently went through this with a batch of Bluegill. I found that while I was doing water changes, I was neglecting to thoroughly clean my filters. I use a series of lava rock, pea gravel, packed sand and filter media. I was cleaning everything, however, the lava rock requires a lot of attention to clean the holes and crevices. This left solids in the filter and this was not showing as a contaminate in any water tests. Once I took the time to really deep clean the filtration system, no more dead fish.

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Hard to pin point the issue with the info you have/gave. As you probably know yourself; fish dying like this is most likely a result of something toxic in the water not a disease.

 

Couple of questions:

 

What is your water source? I am located near a volcano, water comes from springs around it.

 

What do you mean with ppm in waterquality results? salt?? It´s the measure I get from the readings on the sensor, I assume is salts or something like that.

 

Anything made from metal in your system? (other than stainless steel). I have seen rainbow trout dying from water collected on a zinc roof with galvenized gutter.  Small brass pieces from the airstones (those you use to connect the hose) -- other than that, no metal.

 

Do you use soft pvc hoses in your system? (might leach plastizer) No. Everything is hard pvc.

 

Did you use bathroom silicon? (potential anti-mould agents) There are only couple of points where there is silicon, not much - the silicon I got is the one specifically for underwater conditions (according to the label); but I used that on just a couple of uniseals, and outside the tanks.

 

Stray voltage on the water? from 0.7 to 1 volt.

Edited by Krantz (see edit history)

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I looked up a safety data sheet for the chemical levomenthol, it lists aquatic toxicity

 

LC50/96hours as 18.9mg per liter (fish)

that stands for lethal concentration to kill 50% of the fish

menthol is listed the same and  species tested was fathead minnow

 

so I guess that is certainly a possibility. it seems likely that peppermint roots would exude chemicals when the leaves are pruned. it is used to kill invertebrates and as an anaesthetic for fish.

seems like a long shot! what do you think?

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I looked up a safety data sheet for the chemical levomenthol, it lists aquatic toxicity

 

LC50/96hours as 18.9mg per liter (fish)

that stands for lethal concentration to kill 50% of the fish

menthol is listed the same and  species tested was fathead minnow

 

so I guess that is certainly a possibility. it seems likely that peppermint roots would exude chemicals when the leaves are pruned. it is used to kill invertebrates and as an anaesthetic for fish.

seems like a long shot! what do you think?

 

I really appreciate this information. I will inmediately remove all the non-essential plants tomorrow.

 

Thanks a lot!! :) 

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you will need to take the roots and some of the media it is growing in as well I think. plus a few water changes over time. from what I read these types of molecules are not readily biodegradable.

 

i wouldn't stop looking for other reasons, perhaps post your observations or some photos, it might trigger a thought from someone.

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Hi Krantz

 

First of all could you satrt a build thread of your own and show us some pictures of your systems on it...That would be good to see for us who are visual people.

 

Secondly, Do you have any aeration going to your IBC fish tanks?

 

Thirdly what was in the IBCs before you made them into fish tanks?

 

And Do you have any other type of filtration apart from your grow beds with your system?

 

Cheers.

Edited by bigdaddy (see edit history)
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Hi Krantz

 

First of all could you satrt a build thread of your own and show us some pictures of your systems on it...That would be good to see for us who are visual people. sure! I will take pics and upload them later today

 

Secondly, Do you have any aeration going to your IBC fish tanks? There are 6 air pumps, 2 of them are connected to a network of small (1") airstones as well as the the mineralization tanks, and also each fish tank (4) has its own 60 lpm air pump with an 8" airstone.

 

Thirdly what was in the IBCs before you made them into fish tanks?  I don't know, they were already clean when I got them, and when I cut them open I wash them again with a high pressure water pump.

 

And Do you have any other type of filtration apart from your grow beds with your system? No, no other filtration, only the grow beds.

 

Cheers.

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Hi Kranz,

 

Trout need clean water and plenty of air.

 

I would concentrate now on installing extra filtration such as a radial flow separator or swirl seperator and I would also add a moving bed biofilter ASAP.

 

There are basically 3 (there are more) reasons why you need extra filtration.  

 

1. You have trout which are less tolerant to poor water quality. 

2. 240 trout in 4 IBCs is a very heavy load.

3. You have a raft set set up for your plants.

 

Cheers.

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I believe this is a combination of the diet and water chemistry. Trout are weak when it comes to parasites . Lily and similar aquatic plants carry many parasites they can attack fish or people.If water flow depth temperature ect. Oxygen ph Have to be perfect for proper growth they also need great deal of protein. I refuse to buy trout salmon or and commercial farmed fish because of the treatments food and dye they put n meat to make long reddish pink.If you are not interested in eating the fish try goldfish or roseyreds family.doesnt matter u loose them as much as tilapia or other edible fish. Carp are edible and hardy maybe try them if you keep having problems.

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Hi Kranz,

 

Trout need clean water and plenty of air.

 

I would concentrate now on installing extra filtration such as a radial flow separator or swirl seperator and I would also add a moving bed biofilter ASAP. Each sytem has a 200 ltrs swirl filter -- do you think that is not enough?

 

There are basically 3 (there are more) reasons why you need extra filtration.  

 

1. You have trout which are less tolerant to poor water quality. I will post pictures of my systems and the water as well -- you see, my water doesn´t have any floating solids, just looks with that particular color of an aquaponic system (slightly yellowish-greenish)

2. 240 trout in 4 IBCs is a very heavy load. I would assume so, right now I only have less than 50 :( the rest died.

3. You have a raft set set up for your plants.

 

Cheers.

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I believe this is a combination of the diet and water chemistry. Trout are weak when it comes to parasites . Lily and similar aquatic plants carry many parasites they can attack fish or people.If water flow depth temperature ect. Oxygen ph Have to be perfect for proper growth they also need great deal of protein. I refuse to buy trout salmon or and commercial farmed fish because of the treatments food and dye they put n meat to make long reddish pink.If you are not interested in eating the fish try goldfish or roseyreds family.doesnt matter u loose them as much as tilapia or other edible fish. Carp are edible and hardy maybe try them if you keep having problems.

Can you point me in the right direction as to what species to utilize?

Here is my problem: the water on winter can go down as much as 6c (42f), while in summer it goes up to 19c (66f) --- Tilapias are great on summer, but they die miserably on winter... trouts pretty much stand the temp, but they are extremely sensitive.... do you know of any "4x4" fish? some sturdy fish just to produce enough poop for my system to run? I do not intend to sell / kill fish, I just need them to poop.

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I would keep with the trout

Still add your filtration as suggested ASAP because you need to filter what is coming out of the fish even with 50 in 4 IBCs when happy,the trout feed and poop and wee good.

Also do as Yahoo suggested, remove that plant. But I do stress it is important to have good filtration.

Cheers.

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More problems occurrs carp goldfish and roseyreds can take wide range of temperature and can be supported on low nutrient diet. Super harder fish carp are if keeping fish alive is your major problem.

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More problems occurrs carp goldfish and roseyreds can take wide range of temperature and can be supported on low nutrient diet. Super harder fish carp are if keeping fish alive is your major problem.

So you suggest I should add carps to the tanks that currently don´t have any fish?

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Carp koi goldfish or roseyreds tend to be less costly and easier to raise. Carp you can eat and are harvestable normally at 5 years but at larger size so you could haverest sooner. If you want easier fish than tilapia carp best for AP. You just raising fish id suggest catfish crappie or bass for food. Tilapia really best it gets with warmer weather but carp can take way cooler temperatures.

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Hi Krantz,

 

To avoid confusion on your part, I advise you to ignore posts by MikeRich because, even if you can read them, we discourage people who have no experience of aquaponics from dispensing advice about AP systems.

 

Gary

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Hi Kranz

 

Why put carp in a system that has an issue/s? Why put any other fish in to a system that has issues?

 

Identify the issue quickly, resolve the issue/s and keep with the fish you already have...

 

Your temperature range is good, your air is good, you still have 50 trout which are the fish you chose so I would fix the problem add extra filtration and enjoy bringing up your trout.

It's the fish you chose and there is no reason why you shouldn't continue.

 

It's not hard to make up your extra filtration and it will serve you good for all types of fish you wish to grow in the future.

 

For now, I would just keep to the trout...Yes, the filtration is important but once you have that properly set up and your water is kept good, your fish are feeding well, you can quickly grow out your trout, ready for six months of growing tilapia in the summer time.

 

One of my first sytems was a trout system and I grew mine from 4" fingerlings to nice plate sized fish in 6 months around a similar temperature range to you...What's more, I grew some lovely vege's to boot

 

If I were you Kranz I would resolve my issue's, put 25 trout each into 2 of your IBC's leave the others for now...Add your filtration units and raise the trout you have left from those 2 IBCs.

 

I'll leave it up to you now.

 

Cheers.

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Hi Kranz

 

Why put carp in a system that has an issue/s? Why put any other fish in to a system that has issues?

 

Identify the issue quickly, resolve the issue/s and keep with the fish you already have...

 

Your temperature range is good, your air is good, you still have 50 trout which are the fish you chose so I would fix the problem add extra filtration and enjoy bringing up your trout.

It's the fish you chose and there is no reason why you shouldn't continue.

 

It's not hard to make up your extra filtration and it will serve you good for all types of fish you wish to grow in the future.

 

For now, I would just keep to the trout...Yes, the filtration is important but once you have that properly set up and your water is kept good, your fish are feeding well, you can quickly grow out your trout, ready for six months of growing tilapia in the summer time.

 

One of my first sytems was a trout system and I grew mine from 4" fingerlings to nice plate sized fish in 6 months around a similar temperature range to you...What's more, I grew some lovely vege's to boot

 

If I were you Kranz I would resolve my issue's, put 25 trout each into 2 of your IBC's leave the others for now...Add your filtration units and raise the trout you have left from those 2 IBCs.

 

I'll leave it up to you now.

 

Cheers.

Definitely, agree on that -- It´s useless to add more fish to a sick system; I need to work on resolving the potential toxic issue first, and then worry about introducing other fish.

Do you have any DIY filter designs I could get my hands on, by any chance?

 

Thanks a lot.

Edited by Krantz (see edit history)

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There are quite a lot of posts and threads in this forum about filters

 

I remember haveing a conversation with Gary and Crusty at the time AKA Paul trying to get into my thick head the basic principle/s of filtration...Once I got it and it is not hard I was right.

 

I can't quickly direct you to the posts and others setups on this forum but you can use the search function and I'm sure others can help you in that area.

 

I would start another thread with a title something like filtration questions or what ever title you want and ask away there and keep this thread for this issue here.

 

Just as a quick teaser

 

I basically made a radial solids sperator using a 200 litre tub similar to the blue barrels and you could even cut the top out of one of them and use a clean blue barrel or any plastic barrel for that matter and used some PVC fittings to make up the separator....For my Moving bed reactor I used another 200 litre tub added some (this stuff is expensive but the best) K 1 or 3 (can't quite remember which one is is the smaller one anyhow) dropped a large airstone or two or three down the bottom and filled the tub up with water and finally I had a 200 litre sump in which I placed my pump...So water went from my fish tank/s to my solids separator to my MBBR to my sump to my grow beds and back to my fish tanks...

 

That's enough for now. We can talk more in depth about that in another thread if you want to start one up.

 

Cheers.

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http://aquaponicsnation.com/forums/topic/9175-5-gallon-radial-flow-settler-dual-outlet/

 

I think this is close to the latest thinking on filtration here, it reduces the flow to the radial flow filter and keeps it small and compact as it is only removing solids from the fish tank. the rest of the flow goes to the moving bed or netting filter.

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Several posts ago, you mentioned removing all of the plants from a system. 

 

Depending on your circumstances, that can trigger several negative impacts.  I'd caution you to ramp up your water testing when you do it....and react appropriately.  All of which assumes that you have fish in the system.

Gary

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Several posts ago, you mentioned removing all of the plants from a system. 

 

Depending on your circumstances, that can trigger several negative impacts.  I'd caution you to ramp up your water testing when you do it....and react appropriately.  All of which assumes that you have fish in the system.

Gary

Actually I meant only removing those plants that are not there for food production.... they are just two plants -- BTW I already remove them; the roots of the levomenthol were extremely deep into the growbed, very nice menthol smell everywhere.... I really think that was the biggest issue....

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in my experience it is more likely that this is a " the last straw that broke the camels back" situation. I am only saying that because where livestock is concerned it is rare for just one thing to kill something. They are usually already struggling from other issues.

 

where are the fish waste solids? if you are not removing them and they are not in the bottom of the fish tank, they must be somewhere in the system. I guess it will be in the growbeds or the bottom of the raft tank and some of the churned up  fines could be hanging in the water column.

 

some sludge or a dead fish laying in a pipe wont do the fish any favours.

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