Jump to content
Sign in to follow this  
helomech

Catfish dying?

Recommended Posts

Adding acid will lower it, but I don't believe alkalinity is the problem, I generally run 100 to 240 depending on how much I have to top up as I have 300 alkilinity from the tap. Your alkalinity will lower on its own as the nitrification process consumes it, it's a matter of getting it to the point that it consumes it faster than it is raised during top ups.

At this point, given your numbers, I would be looking at some form of contamination, the ammonia , ph, nitrite, nitrate and alkalinity levels are all at operable levels.

The water temps might be suspect if you have way low drops in the morning, but unless your dropping below 50f, I doubt that's it.

Are the fish moving about now? You might start lightly feeding and see if they attack the food.

It's kind of a long shot, but if your withholding feed and your water quality is good tilapia can get very aggressive and attack each other as well as other fish. It may just be the tilapia are causing the fish kills now.

Thanks

Don't have a clue what could be contaminating. I had 50 bass and perch in the system for 4 months before I got the tilapia and not a single one ever died. Nothing has changed other than the fish.

Water temp only vaires about 2f from day to night. Never gets below 66F.

Wife says the fish are moving good, and feeding good. We held feed back for almost a week to get the levels to this point. She feed them yesterday for the first time.

Didn't know that about the tilapia, we are going to start feeding them now and watch the ammonia and nitrite levels.

You guys are great.

Share this post


Link to post
Share on other sites
unless its forming a thin sheet around an 1/8th inch then that one drop will not areate much at all. The setup you have described sounds like it should have no problem with air, so as long as you are not doing a major water change, I would not worry about it too much. A 50 % or higher water change might give issues.

BTW, Are there any metallic components in your water? High copper and zinc levels can kill fish and many people had used galvanized tanks only to loose fish like crazy to poisoning.

Thanks, I sure do appreciate all of you helping me.

There is one brass fitting, and a few brass clamps on my pex pipe. But other than that all plastic.

Not sure what you mean by a thin sheet 1/8th inch?

Share this post


Link to post
Share on other sites
The only other thing that comes to mind is Iron from the well but you have grown fish in this set up before yes?

It is a new system, but I had bass and perch in it for 4 months with no dead fish. That is why I thought it was safe to get tilapia.

Share this post


Link to post
Share on other sites
could be well water has lots of co2 in it? De gas water first? (run airstones through it?) also possible is fertilizers in well water if near agricultural land?

or other nasties like earthangroup said iron etc...

Maybe you want to add some activated carbon to filtration system, see if it helps..

Thanks

Nothing agricultural around me, just pine plantations. We have been drinking the well water straight out of the well for 6 years now. Also use if for our indoor aquarium and all animals. It is also the same water that fills my pond (by natural springs) and my pond is full of fish. Might need to bring some water to the county and have them test it.

How do you de gas water?

Tomorrow I will add lots of air to the water. Just can't do anything till I get back to land.

Share this post


Link to post
Share on other sites

Same thing again today, 3 dead tilapia and one dead catfish. I think when I get home I am going to build a cage that floats to put in my pond. Move all the fish to the cage and see what it going on. My ph is 8.2 again today, was 7.4 yesterday. No water was added (it did rain last night). Getting very frustrated.

Ammonia is 0

Nitrite 0

Nitrate is either 10 or 20 she can't tell

Edited by helomech
added that it rained (see edit history)

Share this post


Link to post
Share on other sites

by thin sheet I mean the water is falling like a water fall with very high surface area, so the as much water is exposed to air as possible. Air stones in the water will degas it, yes you are correct. I am stumped as to why the ph went up as it rained, that would normally drop it. It suggests that something might be dissolving in your growbed. I'm afraid I'm running out of ideas.

I don't think it's lack of oxygen, as tilapia when they die from lack of oxygen often have the mouth wide open as if gasping for air. None in the picture shows that.

Share this post


Link to post
Share on other sites
by thin sheet I mean the water is falling like a water fall with very high surface area, so the as much water is exposed to air as possible. Air stones in the water will degas it, yes you are correct. I am stumped as to why the ph went up as it rained, that would normally drop it. It suggests that something might be dissolving in your growbed. I'm afraid I'm running out of ideas.

I don't think it's lack of oxygen, as tilapia when they die from lack of oxygen often have the mouth wide open as if gasping for air. None in the picture shows that.

Thanks, I really appreciate your help. If you come up with any other things for me to check or ideas please post here.

Oh, okay. I do run one of my pumps with a spray that is flat. I just smashed the end of a PEX pipe and it gives a nice flat spray. Going to check my water temp in my pond and if it is high enough will move the tilapia to there until I figure out what is going on. Will build a box to put them in. That way I can feed them all they can eat without worry. The pond is 1 acre and 14 feet deep. Then will drain my system down and check everything.

Share this post


Link to post
Share on other sites

If it rains and your Ph goes up.. I have a question are you using gravel media any place in your system. There is some gravels that will raise you Ph that are not Limestone. Some marble based gravel have a Ph value that seems to show up when it rains for the sole reason that rain water is a little more acidic which causes the PH to be released.

Are there any farms near by? if so if they are spraying it doesn't need much to kill the fish. Is it possible that there is some kind of outside pollutant that has gotten into your pond?

How big is this pond any way when this started you were using a tank?

Share this post


Link to post
Share on other sites
If it rains and your Ph goes up.. I have a question are you using gravel media any place in your system. There is some gravels that will raise you Ph that are not Limestone. Some marble based gravel have a Ph value that seems to show up when it rains for the sole reason that rain water is a little more acidic which causes the PH to be released.

Are there any farms near by? if so if they are spraying it doesn't need much to kill the fish. Is it possible that there is some kind of outside pollutant that has gotten into your pond?

How big is this pond any way when this started you were using a tank?

Thanks

I am using a 1550 gallon plastic tank I bought new from tractor supply. I also have a pond on my property (it is over a acre), but will only use that to hold the fish till I figure out why they are dying, if need be. The pond is totally separate, only mentioned it because I may use it to hold the fish for a little while. Might give me time to get all my readings correct. The pond has nothing to do with the aquaponics, other than maybe keeping my tilapia alive till everything gets working properly.

I am using river rocks in my grow beds, also have some slag rocks in the bottom of the grow beds, but will not be using those on my new grow beds. The new ones will just be river rocks. I tested the rocks with vinegar and so no bubbles coming off the rocks.

No farms within miles of my place and any of those will be a lower elevation than my place. I am on the highest spot in the county. Only things I can think of is there are a couple metal fittings in my tank. One galvanized fitting, and 2 brass clamps on the PEX pipes. Also have a metal strap holding my pump up, going to be removing all those tomorrow, and going with plastic only. Could these be killing my fish?

Share this post


Link to post
Share on other sites

I would highly suspect the galvanized fitting, zinc is poisonous to fish and like ammonia, the higher the ph the more the toxicity. Have your wife throw in some vitamin c tablets as this will neutralize some some toxins and it helps fish deal with stress. I use 1000 mg tablets at a rate of 1 per 75 gallons. So about 20-25 or so for your system. Going a little over will not hurt.

Share this post


Link to post
Share on other sites
I would highly suspect the galvanized fitting, zinc is poisonous to fish and like ammonia, the higher the ph the more the toxicity. Have your wife throw in some vitamin c tablets as this will neutralize some some toxins and it helps fish deal with stress. I use 1000 mg tablets at a rate of 1 per 75 gallons. So about 20-25 or so for your system. Going a little over will not hurt.

Cool thanks will let her know right now. Just seems so odd that the bass and perch did not mind.

Where do you get them? Wife is not sure where to look.

Edited by helomech (see edit history)

Share this post


Link to post
Share on other sites

those dead tilapia you posted, are they freshly removed? that white film over the eyes .. Do they have frayed fins aswell? Put live fish in glass of water to see best. If they have white bits starting on fins, and fins are decayed , with whitish sloughing off, you probably have a bacterial or fungal infection. Prepare a salt dip tank (bucket etc..). put tilapia in tank water with 10grams salt per liter added to it , well dissolved ,for 20 minutes with lots of air (airstone in it). do it every day for 3 days running, and also salt youre growbed fishtank with half a cup .

Also remove all metal bits in tank, doesnt help.

keep us posted

Edited by mopa (see edit history)

Share this post


Link to post
Share on other sites
those dead tilapia you posted, are they freshly removed? that white film over the eyes .. Do they have frayed fins aswell? Put live fish in glass of water to see best. If they have white bits starting on fins, and fins are decayed , with whitish sloughing off, you probably have a bacterial or fungal infection. Prepare a salt dip tank (bucket etc..). put tilapia in water with 10grams salt per liter for 20 minutes with lots of air (airstone in it). do it every day for 3 days running, and also salt youre growbed fishtank with half a cup .

Also remove all metal bits in tank, doesnt help.

keep us posted

Thanks.

Not sure how long dead, sometimes they stay on the bottom before they float up. But the live ones look fine, at least that is what my wife says. I will know more tomorrow, I should get home late tonight.

The metal bits will be gone tomorrow.

Share this post


Link to post
Share on other sites

also note the fish have emaciated bellys. not eating correctly. (sign of something up) The fungal/bacterial growth can also cover gills/ destroys them and makes it difficult for them to breathe.

Hopefully its just a a fungal infection and salt will sort it out. make sure you use pure sea salt no additives. or pool salt

Share this post


Link to post
Share on other sites

Probably the fish have been infected for quite a while now, but as viewing from top cant see anything wrong. You could ask wife to put pure sea salt in tank until you get home.

The salt might kill the catfish though. fingers crossed for you. regards

Share this post


Link to post
Share on other sites
also note the fish have emaciated bellys. not eating correctly. (sign of something up) The fungal/bacterial growth can also cover gills/ destroys them and makes it difficult for them to breathe.

Hopefully its just a a fungal infection and salt will sort it out. make sure you use pure sea salt no additives. or pool salt

We had been holding back feedings because of high nitrite levels. Just got the levels sorted out yesterday and started feeding again.

Thanks

Share this post


Link to post
Share on other sites

also what type of plastic is youre tank?

Got a feeling catfish were infected and when you put tilapia in, the filtration bacteria couldnt handles the sudden bioload, bad bacteria and fungal explosion occurred when feeding the sudden large party. I would also do 50% water changes for a couple of days to try and drop bacterial/fungal load % in water. Do large changes or bacteria/fungus will quickly multiply to max levels in small water changes. A uv sterilizer is also a great back up kit to have for these cases.

Share this post


Link to post
Share on other sites
also what type of plastic is youre tank?

Got a feeling catfish were infected and when you put tilapia in, the filtration bacteria couldnt handles the sudden bioload, bad bacteria and fungal explosion occurred when feeding the sudden large party. I would also do 50% water changes for a couple of days to try and drop bacterial/fungal load % in water. Do large changes or bacteria/fungus will quickly multiply to max levels in small water changes. A uv sterilizer is also a great back up kit to have for these cases.

It is Polyethylene. Here is the exact tank I have.

http://www.tractorsupply.com/storage-tank-1-550-gal-65-in-h-x-87-in-dia--2125652

We had been doing water changes. We would dump water for about 2 hours while constantly adding new water. Done that 3 times this week. Some of the catfish did have white spots, but never seen any on the tilapia. We treated the water with something for ick (spelling), can't remember what it was called.

Weird thing is that I had more fish weight with the bass and perch. The catfish barely weighed anything and the tliapia where small aslo. Some of the bass weighed a couple pounds each.

Share this post


Link to post
Share on other sites

most of the time bacterial infections/ fungal infections occur as an after affect of the fish having a hard time with either external / internal parasites, or bad water chemistry. The fish are used to living in bacterial laden waters, but get affected when their immune system has been weakened by other things first .

Hopefully it is just a bacteria / fungal problem.

This might help you identify

Tilapia-diseases-Intervet-Tilapia-workshop-June-09 photos v. imp!!!.pdf

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...