How I DECIMATED my aquaponics system and I have no idea why!

[David - WI]

This is all I've go for you, the whole thing is worth reading: http://www.reefkeeping.com/issues/2007-05/rhf/#11

[Jeff]

Thanks David - I am going to read that over right now. While I do, let me ask you this. In YOUR system, do you notice as wide a range in pH swings? I personally never knew that pH could swing do drastically from daytime to nighttime, so I am left to wonder if my system was always like that, or if it's more extreme now due to an imbalance of plants vs fish.

So does your system swing that wildly? If you said no, then I know that there's definitely something amiss with mine. However, if yours also has that range of swing during a 24 hour period, then that would tell me that it's normal and not something I should be focusing on for the problem.

[David - WI]

I honestly don't know... I've never gone to work at night to check the pH; plus I'm only testing ideas right now so I've been moving plants & crayfish around and mine is in a climate controlled building with almost all artificial light - so day & night don't mean much.

I honestly think that if you ran more in the mid-to-high 6's then your "spikes" might only go into the mid-to-high sevens and you could forget about ammonia toxicity?

[David - WI]

By the way, last week I had 6,000 gallons of water cycled and after 3 weeks of fighting (and 3-1/2 gallons of HCL) the pH bounce... the tank ruptured and leaked 5,000 gallons out on my floor overnight.
So, I made a quick silicone patch and refilled the tank.



And the patch didn't hold and I leaked another 5,000 gallons on the floor the next night. So, I'm here more for moral support than "expert" advice.

[JCO]

Forget the plants..they will survive without the fish...do you have another receptical you can house the fish in out of the AP system...anything that will hold water with a sponge filter and air stone. Do not add salt to it, just the fish then we will see if anymore parish.

[Jeff]

Forget the plants..they will survive without the fish...do you have another receptical you can house the fish in out of the AP system...anything that will hold water with a sponge filter and air stone. Do not add salt to it, just the fish then we will see if anymore parish.

JCO - Yes and no. Here's what I have done thus far (it's literally a day-to-day thing, with new theories and approaches to this perplexing problem).

I had an old turtle terrarium tank which hasn't been used for years. It's about 20 gallons to the top. I cleaned that out, filled it with about 15 gallons of water, and put in that really sick (dying) koi, as well as my last ornamental fantail goldfish who looked a little lethargic. When I set that tank about (almost a week ago), I did have salt in the water 0.3ppm. No more salt has been added to that tank. I also have been treating that tank with Maracyn Two, just as an anti-bacterial precaution. The tank has an airstone and a filter for moving the water around.

After almost a week, both fish look the same in there. I am wondering when this koi is going to die because he appears to just be hanging in there. I don't see him eating or improving. As for the fantail, he looks the same as well, but he's eating and swimming around, so I'm not concerned about him. He will move back into the main tank either today or tomorrow.

Now onto the main tank.........

My current theory as to the problem has NOTHING to do with ammonia, or disease (although I agree that some fish may be fighting some kind of illness due to the past issues). My current theory is that my fish are slowly dying from large DIURNAL PH SWINGS.

You see, I NEVER considered to check PH twice a day, nor did I know that pH could swing so wildly in a 24 hour period. It appears that my pH was swinging more than 1.0 point, from the high 8's to the low-mid 7's. That meant that at night, when the water was very alkaline, it would change to very acidic in a matter of 10-12 hours. I think this may have been the main cause of either KILLING the fish outright, or making them sick and weak to succumb to something else later on.

MY MISTAKE - I assumed that three powerful grow beds returning water to the tank would be enough "aeration" to prevent these large swings. Apparently, I may be wrong about that. So last night, I went out and purchased a 4-line air pump, made for 170 gallon tank, and I put all four lines into the tank at full blast. From my research (thanks to the article David posted above), it says that AERATION will help minimize large pH swings.

I never knew that! So here's where we stand. I am currently aerating the CRAP out of my water. I have that air pump running 24/7, in addition to the 3 grow beds returning the water during the siphon cycle, and my Radial Swirl Filter constantly pouring water back into the tank as well.

We will see if that will minimize the pH swings and help the fish.

That's where I am right now. I don't know if the pH swing was the initial cause of all these fish deaths, but I do know that it's a PROBLEM regardless, and it needs to be corrected. That's my focus right now and I will keep you posted on how it goes. So far, this morning I had no dead fish (although I'm only down to 5 in that main tank).

[Roger L.]

Jeff, I just thought of something that relates to your last post. All of this began to happen after two years of successful operation right? If so, have you cleaned the grow beds out in that period of time? If not the water may be channeling thus losing some aireation properties you enjoyed before. This would all match the facts that you have ph swings and the heat factor all effecting the oxygen content of the water. Just another newbie thought.

[Jeff]

Roger - I did consider the problem happening with the grow beds (since they have never been cleaned out), but I never thought that it would do with aeration. I was thinking perhaps it was something anaerobic or something poisoning the water........but now that I know for a fact that my pH swings are really drastic, it would make sense that something effected the CO2 levels of the water.

I honestly think that may have been the issue: lots of fish, hotter temps = less O2 in the water and more CO2......which lead to big acidic/alkaline swings in short 12 hour periods, and that stressed/killed the fish off. It was like a perfect storm.

Hopefully, with this new 170 gallon 4-line air pump, it will stir the air from the bottom of the tank 24 hours a day, and help equalize the CO2 levels. I will keep you all posted.

[Roger L.]

Still need to clean those beds. Take one off line and start cleaning. When that one is done, move to the next. Good luck.

[Jeff]

Still need to clean those beds. Take one off line and start cleaning. When that one is done, move to the next. Good luck.

Yeah, my plan is to clean during the cooler months when they're relatively empty and not producing. I may have mentioned it previously, but two of my grow beds have established plants in there (peppers) which I don't want to "kill" by yanking the root ball out of the bed. I fear it would kill the plants if I do that.

Now, one bed that I have doesn't have any peppers in it, so it will be easy to empty and clean (well.....easy for a 300 pound tub filled with hydroton!). The others though.......I am thinking about flooding it, stirring around the floating media (away from the plant roots), and then draining into an empty part of my yard. I would repeat this until most of the gunk in there is flushed out and the water is coming out clearer.

I know that's not the best approach to really "CLEAN" the beds, but it may be my best shot without removing the established plants in there.