Are tomatoes toxic to fish?

[Jason Yahner]

Half of a tomatoes was found floating in our tank. Could this be a cause for our fish dying off over the last two days?

[TCLynx]

How big is your system?

What do your water tests say?

I wouldn't expect half a tomato to kill fish but then again if your fish tank is just a beta bowl I guess half a tomato could cause some drastic changes, depending on the size of the tomato.

[Todd Sowell]

Were there any tomato leaves in the tank. The leaves can be poisonious to pets and I'm sure fish too

 

Todd

[mary proctor]

I did not know that.....tomatoe leaves are poison to fish and to pets.  Where did you get your information.

[TCLynx]

tomato leaves contain alkaloids which are not good for people or pets to eat I know.  But apparently they don't seem to hurt caterpillars.

[Todd Sowell]

Mary,

 

i was just at a home show showing my system and a ER vet service had fliers of poisonous plants with tomatos on it.

I was surprised too!
 
mary proctor said:

I did not know that.....tomatoe leaves are poison to fish and to pets.  Where did you get your information.

[Ryan Chatterson]

It's in the nightshade family.

[Rachel]

I've had mystery death in my tank for nearly the entire time I've been doing aquaponics (about 2 years). It has always seemed strange that my smallest fish died first. My chemistry has always been normal, and finally today it occurred to me to pull the tomato plants. I have an IBC system with the plants directly above the tank, so occasionally leaves, flowers etc would fall into the tank. I've pulled all of the tomato plants (6 HUGE ones) and got most of the roots I could, though I'm sure there are still a bunch in there, I assume those are toxic too, but I guess all I can do is a big water change and hope for the best. Any other recommendations? (Interestingly, I put gambusia in there a couple of months ago and they're doing just fine).

[TCLynx]

I've grown plenty of tomatoes but I've never grown them where they can drop leaves into the fish tank.

[Eric Warwick]

This is more adequately explained by the fact that tilapia are territorial in nature and will push the small fish to the bottom.    If there is decomposing fish food then the localized water conditions, primarily oxygen, will be affected. Look for any sudden rises in Nitrates, Nitrites, and Ammonia (NH3 will show up first) after feeding heavily. Make sure to test regularly for the next, say, month, and record how much you've fed in grams (it's easier to convert later). If there is a larger than normal rise feed less. One way to help with this is the 5 minute rule: feed, wait five minutes, and scoop up the rest. I've found standing back, so the fish can't see you, is helpful. (Well, my system went through a lot and the fish have made this equation in their heads human=going into a non-water environment for a few seconds and in a bucket for my home to be filled with algae free water). Post your results on the forum so everyone can see the precious, precious data. 

Rachel said:

I've had mystery death in my tank for nearly the entire time I've been doing aquaponics (about 2 years). It has always seemed strange that my smallest fish died first. My chemistry has always been normal, and finally today it occurred to me to pull the tomato plants...

[Rachel]

Yeah, I've been through that bit, it made sense to me when I had large fish in the tank but recently I ate the last large tilapia and the largest of 20 new fish in my ~175 gallon tank are a little over an inch long and I'm feeding them a tiny amount of food a couple times a day (not enough to cause a spike even if none of it were eaten) and they're still dying. I'm hoping it's the tomato because that seems like the only variable I haven't addressed.

Eric Warwick said:

This is more adequately explained by the fact that tilapia are territorial in nature and will push the small fish to the bottom.    If there is decomposing fish food then the localized water conditions, primarily oxygen, will be affected. Look for any sudden rises in Nitrates, Nitrites, and Ammonia (NH3 will show up first) after feeding heavily. Make sure to test regularly for the next, say, month, and record how much you've fed in grams (it's easier to convert later). If there is a larger than normal rise feed less. One way to help with this is the 5 minute rule: feed, wait five minutes, and scoop up the rest. I've found standing back, so the fish can't see you, is helpful. (Well, my system went through a lot and the fish have made this equation in their heads human=going into a non-water environment for a few seconds and in a bucket for my home to be filled with algae free water). Post your results on the forum so everyone can see the precious, precious data. 

Rachel said:

I've had mystery death in my tank for nearly the entire time I've been doing aquaponics (about 2 years). It has always seemed strange that my smallest fish died first. My chemistry has always been normal, and finally today it occurred to me to pull the tomato plants...

[Eric Warwick]

Well, the leaves in the tank would cause high nitrates, but you might want to look into the tomato leaves.

[Jason Yahner]

That tomato was a actual half of a tomato in the tank. I have tomatoes in the grow above the tank but no leaves have ever entered the tank( the tomato was human error). I recently adapted a gravel cleaning siphon so I can clean the bottom of the tank before I put 20 Tilapia in to replace all the 50 small catfish I lost. Chemical levels all seemed fine. Better data recording is in order.