Backyard Aquaponics
A place to discuss aquaponics

I live in central Indiana and have been building my first aquaponics system in my breezeway. Enclosing it with double layer plastic as weather cools this fall. Have a 250 gal tank..some good pumps, good aerators..so it seems. They are working continual with no fail. I "seeded" the tank with 2 lbs of bass minnows, and 1 lb of Goldfish minnows. I had searched and asked as much where ever I could before seeding concerning mixing of breeds and didn't find anything to the contrary. Tank ph is steady at 7.0.

The fish for first 2 days seemed to acclimate wonderfully. Feeding Goldfish Flakes and all seemed well. Then calamity set in. Although the bass seem to flourish, seem healthy, active, and still acclimating. Every day I end up with about 12-15 dead bass. Every day! Checked everything I can think of. They show no signs of anything but health. Fairly convinced that if it was disease or bad feed disagreeing there would be more than just a handful die per day, there would be a major number die. They would not be acting so healthy and active and seem happy.

My only conclusion is I have a Bully Goldfish that is aggressive towards the bass. Everyday I have anywhere from 12-25 that are dead.

Can anyone advise of experience with mixing breeds. My only recourse seems to be wait until the Goldfish have killed off all the bass remove them and start again. I am pleased to have found this forum where can associate and learn from experienced people that do what I am trying to do.

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Welcome to the forum and can i say, I KNOW your stress. oh how I know it..

You can THINK you know the theory and still, disaster strikes, and you are forced to rethink, just how much you know..
If you have lots of money, you can test as they would in CSI for every nastie .. alas testing can be more expensive than the fish..

How well cycled was the system.. three pounds of minnows seems massive ..

What are your ammonia and nitritries..?

Water change might help.. to kerb the slaughter.. if the bass seem to by acting crazy, scatty, and then roll over and eventually die, then that is what I have seen..

I have another system.. My killer system... I know not what it is in that system, but Koi (and surely Goldie's) do fine, but 96hrs of inclusion of trout or Silvers, sees them all dead.. LC100

The Point.... some fish are massively more sensitive to their Environment .. and you may have been better starting with a smaller amount of Goldie's and cycled the system properly, allowing the bacteria to develop..

For further guidance, you had better describe the full system, including the Bio filtration included.. ie. Both any filtering and the construction / volumes of grow beds..

You could add some calcium carbonate as a first action and you could add salt to help the fish...

Where did the water come from.. ie. Was it rain water or town water.. what treatment to that water..

More information and more folk will chime in and make suggestions..
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The system was up and running for 3 weeks...the ph was right 7, water temp is a consistent 68-70 degrees , it is a huge 275 gal tank with an overflow about an inch over the 250 gal mark..so there was plenty of room, or so it would seem. The bass act all normal as far as I can tell.. Lively and active, keeping good color.... the ammonia on my scale is a level 1 which according to the kit, is far from being excessive. The kit scale and instructions say that a lvl of 5 is the time to start getting worried mark I would have to go write down the type of kit.......

I used all rain water to avoid any city water contamination and monitored the water and constant flow thru the system......for three weeks until I got the ph level up and I am pumping up thru the system then down into a duck weed tank then overflowing thru that thru a bio-metric filter material from the acquarium shop that comes in a sheet and I cut to desired length and place inside a pipe that fills the pipe where it has to filter to get through.

the puzzilng part to me is that only a hand few die every day~not a massive die off...and when it is feeding time they ALL are active as heck diving , coming up to grab a bit of food and take off then coming back to get a bit more....... very active and "spritely" it all seems normal. I have some aquarium accessories i.e. big log shaped placements that imitate the wild.... like I said everything seems as normal as can be......I check the system 3-4 times a day...and feeding morning and night.... and the dieing seems to take place mainly at night..there might be a couple thru the day, but, at morning feeding there will be a handfull (12-30 and all bass) floating dead. I keep thinking that I have checked and checked everything and it is all within the limits, the only thing I can figure is an aggressive Goldie that is still hungry and trying to bite but cant swallow...but, some of the bass are small enough that a Goldie could possibly swallow whole....which makes me think an aggressive "Bully" Goldie........

I have 2 aerators that work wonderfully~no signs of oxygen deficiency at all` and 2 flow pumps that work well.

I have a 1st flush system that fills the fish tank to overflow which goes into a 2nd 275 gal tank which I use the water for garden water and such. This attracted mosquitoes, and I harvest the larvae about 3 times a week by netting out and then net into the aquarium, and the bass go real active attacking and eating the larvae......

Again, it is not a thing of a major die off~ only a handful per day...which, again, leads me to the Bully Goldie with a bad attitude...especially since I seen one attack a bass coming in from lower left and bite then run......the bass immediately slowed down, naturally, and within minutes there was one floating and I assume it was the victim of the attack.....

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I have "decided" that one of my problems is with the rain water from a.zinc roof..
Hence an earlier question about salvaging roof water from a zinc roof..
You see a few die each day.. that is likely just a natural process of the weakest failing first, until there was none..
Same for both metals contamination and high nitrites/ammonia etc..
But.. your description suggests you may not have a nitrogen problem ...

You may be right about the attacks, but I would nit exclude the more chemical possibilities .. but I am FAR from being an expert..
Just a tryer ..

Btw.. I stopped with the duck weed, as I was not convinced that the BlueGreen algae growing amonst the weed was causing problems.. Duck weed is a GREAT nitrate sink..
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Just wondering if its chicken and egg.. weak bass attacked and stressed even more and then hastens death from stress.

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What are your nitrite levels?
Bacteria that convert ammonia to nitrite are usually quicker to establish than those that convert nitrite to nitrate. Do you have sufficient biofiltration and was it cycled?

Nitrites cross the gills and bind with the blood reducing its oxygen uptake. At night your duckweed will be using oxygen as well. The bass might be more senitive to this than goldfish. The effect can be cumulative while nitrites are present. Chloride in salt can help.reduce nitrites moving across the gills. Rainwater will have little salt and offer little protection. Salting to 1 ppt can help.

Just an idea that might explain your losses

I have to obtain a kit to measure the nitrites..but to my understanding the ammonia has to accumulate some first for it to change to nitrites then the nitrates....the way I understand it.......and being the tank is 250 gal...that is quite large for the small minnows.......which live for days and days with just aerator at the bait shop....with no food. So, I am thinking with that much water would/should keep nitrites from getting too large....but, the bacteria bearing nitrites is a valid thought since the system has been in operation for 3 weeks prior to seeding with the fish.

I have a double horizontal tower system that is 4' x 5' with approximately 15 holes with peatmoss as seed nests to capture nitrates. just seeded the nests 3 days ago...and the moss is staying good and moist. Bt, too soon for and sprouts of any kind and with diminishing population chances grow slimmer.

Continuous Flow is pumped into the top rack and by natural (man`made by design) lean keeps all seed beds moist, some more than others then drains down the four towers into bottom rack which the seed beds are the wettest..and drains down into the duckweed pan.....I monitor the duck weed and it is staying pure and clean with the whole system draining into it and on out with same amount of continuous flow.....the duckweed propagates nicely and the fish seem to love it....about every other day I feed a fair amount into the tank......

during this writing my wife interrupted me for dinner....we discussed the fish, coming up with her own ideas....went to the tank to feed to show her how lively and active the bass are and had 9 more bass dead. 2 showed signs of red area curved in shape on each side of belly...and one had part of tail missing......I do have to get nitrites testing kit..but ammonia is still down about 1..not enough to do plant system any good to my belief

I do appreciate your interest in helping with ideas, of course, it is much appreciated! I am in total test and experiment mode and a complete newbie. I research alot but, it does not take long to destroy and lose any confidence one has in knowledge, very quickly.

I will try the salt tomorrow and see what happens.....and obtain a nitirites testing kit. I am 63 and disabled and this has been a large project for me, but an interesting one.

Since finding evidence of the red, bruised looking area on belly of 2 that is oval shaped, combined with actually seeing a Goldie come from underneath and attack and run on a bass, add into that a missing tail on a small one is certainly making me lean towards a bully even though I have never known of GoldFish to be aggressive with other breeds....but, like that old saying...there is one in every crowd.....lol could apply here as well.....

thanksagain for your input...it is invaluable to a newbie....