What's happening to our plants?

[Beth Medeiros]

We have a new system in place and are having some hiccups in our system.

 

We have an IBC tote setup: 3 growing beds, one sump bed and 1 large fish tank with only 10 tilapia in it at the moment. After cycling the system, we added the fish only to then have it be the coldest April in TX in a long time (easily 20 degrees below normal temp ranges).  We actually lost 10 fish (had started with 20) due to cold temp swings.  After rigging the fish tank with some aquarium heaters, we've been able to keep the fish tank above 60F despite temp dipping into the 40's and such.

We've had a hard time regulating our ammonia, nitrites and nitrates.  The ammonia spiked when the cold weather shut down the bacteria and while the nitrites are rising and nitrates are now off the chart, the ammonia levels aren't going down. We still haven't had more than 2 days in a row of warm weather either. Today it's back to the 60's.  We've barely fed our fish in the last week (2x) and they're small (most less than 6 inches).

Today's readings: Ammonia 8ppm, Nitrite 5ppm, Nitrate 80+ppm and pH is 7.0.  But we also have a in-tank ammonia reader that says that the ammonia is low and normal.

 

Our plants were doing well, lettuce is doing fabulously.  And then this last week we started noticing changes in our plants.  Some of our tomatoes plants started breaking at the main stem.  Leaves started changing color, yellowing. One of the watermelon plants has white spots. Basil is stunted, slow growth and looking off.

So, what are we doing wrong?  Ammonia poisoning? Or is it the cold weather?  Mineral Deficiencies?  So many things that we don't know....we thought we had a handle on this but we're finding out this is more of a challenge than we thought it would be.  We are both biologists, so we're up for the challenge!

[Alex Veidel]

Don't worry, it will all improve with age. But, there will always be problems too. One thing that you will have to keep in mind as you journey with aquaponics: you WILL lose plants; you WILL lose fish. It's just a part of learning.

[Beth Medeiros]

I know we will lost plants. We already have.  We've lost half our fish too.  Oh the joys of aquaponics!  :)  I'm the kind of scientist who likes to see immediate results, so it's been challenging for me.  My husband is a little more content to wait and see. 

The cold weather is what's annoying us now because it's not normal and out of our control.  The beds are bundled up for tonight with some flannel blankets and the fish are toasty in their heated home.  not much else we can do.  So in a holding pattern for the next 48 hrs. 

[Harold Sukhbir]

Hi Beth,

You're not in any immediate danger at 6.3ppm just try to dose small amounts of a carbonate to keep the values steady, slightly above 6, at least until you start getting a zero ammonia. Even after you get a zero ammonia you should still continue adding a daily small dose to raise the PH in very small increments. The fish/plants have been through quite a lot of trauma so we don't want to give them any shocks, more than is absolutely necessary.

Beth Medeiros said:

Today:   NH3 - 1.5ppm  (whoo hoo!  It's coming down!), NO2 - 5+ppm and NO3 - 80+ppm

How worried do I need to be that the pH is down to 6.3?

And now we have another cold snap tomorrow night.   I'm trying to figure out how to protect the plants from 37F at night after a rainy cold day.  We'll have the heaters on for the fish, but I so don't want to lose more plants.  I already lost all my cucumber plants after the freeze we had in April. 

 

Please tell me that this isn't as consuming when the system is running correctly!

[George]

Hello Harold

I've read that we should no carbonates to raise PH, that the air supplies all that is needed (seems to make sense) and also that we should be using carbonates.  Nate posted a video on the subject but it seems to be gone.

Would you mind elaborating as to why you recommend a carbonate?

[Harold Sukhbir]

Hi George,

You caught me there! In AP what is commonly used to buffer PH are hydrated lime and potassium hydroxide in equal amounts. If you want to see more look at this discussion we had a while back  http://community.theaquaponicsource.com/forum/topics/ph-level-and-crop  If you have any questions please create a separate post in the forums, thanks

George said:

Hello Harold

I've read that we should no carbonates to raise PH, that the air supplies all that is needed (seems to make sense) and also that we should be using carbonates.  Nate posted a video on the subject but it seems to be gone.

Would you mind elaborating as to why you recommend a carbonate?

[George]

Thanks Harold.  I wasn't trying to catch you at anything.

[Beth Medeiros]

Ok, so it's been a few days of just watching and seeing if our plants would make it thru the May freeze of TX. :). Other than some freeze-dried bean leaves, I think we're good.

Our ammonia levels are holding just barely above 0ppm. Just the slightest tinge of green, so I'm calling it .1ppm. Nitrites still over 5ppm (or at least I'm assuming that because its a brighter purple than the chart has) and nitrates at 80ppm. pH is holding around 6.5 so that is good. At what point do I worry now about the nitrite levels? I thought I read that they could be just as harmful to the system if they're too high.

On the happy side, our cilantro is about ready to be picked which means the first harvest from our aquaponics system. Exciting times!

[Harold Sukhbir]

Hi Beth,

BTW are you still feeding the fish? You ammonia bacteria are working despite the temp fluctuations. The nitrite bacteria are still not present. Nitrite are very harmful to fish and this is a concern here. You have no choice but to wait it out. Try to get some "seed" material(i suggested earlier) and introduce it to the GB's.

[Beth Medeiros]

We had gotten a bunch of seed bacteria but then had the two cold spells.  We've had two warmer days and it's suppose to be in the 80's the whole week, so hopefully no more below 40F weather....or I will cry again!  Did the cold temps kill the nitrite bacteria or is it dormant?  Since the test only goes up to 5ppm, I have no idea if it's actually coming down.  The purple did not seem as deep as it did before, so I'm hoping that it's coming down.

 

The fish have gotten food only the last two days after not being fed for 10 days.  I honestly did not realize that there are different bacteria.  Not sure why not, since it makes sense.  I came into the aquaponics project after my husband started it, so he's done more of the research than I have.  I'm playing catch-up.  :)  It's been too many years since I took all my biology classes. 

[Harold Sukhbir]

Hi Beth,

Yea, feeding them is giving just them more Nitrites. They are alive only because of your low PH(saving grace). Usually with ideal temps, cycling takes about 10-14 days, so please no more feeding, We just have to be patient

[Beth Medeiros]

I'll tell my husband no more feeding...hopefully he'll listen :) 

[Beth Medeiros]

0 Ammonia

3-5 Nitrite

30 Nitrate

6.5 pH

 

I am so glad that our nitrites are finally on the scale! No longer bright purple :)   Our only concern is that our nitrates dropped more than half (down from 80) in 24 hrs. In the meantime, the plants grew two inches overnight. We're thinking that the plants were having a feast. Hopefully, the nitrites will come down significantly tomorrow and we can keep the cycle going with feeding the fish again.

 

We did get to enjoy the first fruits of our labor.  Cilantro last night and some lettuce tonight.  Yummy!