Aquaponic Gardening

A Community and Forum For Aquaponic Gardeners

My tomato plants (5) are growing but not producing much fruit, one or 2 tomatoes in the past 2 months.  A few others on the plants but take forever to turn red.  Any ideas what I can do to increase fruit production??

  • Start Date of IBC was last year June 2014
  • Take size 175 gal  IBC tank
  • 15 - 20 goldfish
  • Using air pump, fill and drain method, transferring approximately 80 gal per hour, my water really clear.  
  • Fish appear to be growing and look healthy.  
  • Location Fort Worth Texas
Most recent water readings
Ph 8.2
Anomia .25
Nitrite 0
Nitrates 80

Views: 411

Replies to This Discussion

Are you hand pollinating?

No i'm not hand pollinating, not sure i would know how?

Danny, I live in the same area just south of Dallas and have the same issue.  Same tank size, fish, etc.  The plants look great but 3 tomatoes, several squash that seem to be growing slowly, lots of flowers.  Only difference is my PH is just under 7 but same results.  I shook the tomato plants to pollinate, not sure what to do with the squash and peas so i am interested in the responses.  

Danny, your PH is a bit high. 

  • Target a pH of about neutral, or 6.8 – 7.0, in your aquaponic system. This is a compromise between the optimal ranges of the fish, the plants, and the bacteria. For fish, this is a pH of around 6.5 to 8.0. For plants, this is a pH of around 5.0 to 7.0 and for bacteria it is a pH of 6.0 to 8.0.

This came from the Gardening Rules of Thumb page. There is a bunch of other really useful info on there you may want to check out.

I agree with the pH statements. You do need to shake the flowers to get them to pollinate. My first aquaponic tomato plants did the same as yours so I decided to just grow them outside. But somehow I did put them back in my system and my DWC is producing quite a few flowers but the media bed is still only producing a few. The outside tomatoes are doing wonderfully. Might be the difference in nutrients.


  Your numbers sound good - a tad high on the pH.  Try to lower the pH to around 7.0 - 7.5.  Tomatoes like the pH to be a bit lower, around 6.8 - 7.3 .  How much and how often are you feeding your goldfish and how big are they.  The consensus on fish to water is 1-pound of fish per 5-gallons of water.  So if you have, say 20, 8-ounce fish, you have 10-pounds of fish.  You will be good to go if you had 50-gallons of water in your tank.  So your system can support more poundage of fish.

  To hand pollinate your tomatoes, just vibrate (shake) the stems below the flowers and they will self pollinate.  For squash, look for a swelling below the flowers.  This is the female flower, the male flowers will not have this swelling.  Pull a male flower off and pull back the petals or strip them off and use the stamens to pollinate the females. Just rub, gently, the two yellow parts together  In a few hours you will notice that the petals of the female will start to curl in towards themselves.  This means that you successfully pollinated the flower and fruit will start to form in about a week.

  I did say to pull the petals back from the stamen on the male flower at first, this is only used if you intend to eat the blossoms.  Filled with cheese and breaded in an egg wash and dredged in breadcrumbs.  Deep fried and served hot...YUM!

You beat me to the pollinating techniques Leo. I was going to get to that when I was at a proper keyboard but oh well. Good job with the explination. Danny and Mike your in good hands with Leo.

Great suggestions by all, thanks.  

I v’ed hand pollinated my plants by shaking them together.  My system has always been outside and I thought mother-nature would have take care of the pollination for me part, anyway I helped her out a little.
I’m going to buy some Ph Down solution to bring down my Ph.
I’m also going to double the amount of goldfish in my tank.
I’m very thankful for everyone suggestion, If you have any additional suggestion or comment I welcome them all.

SAD NEWS, in trying to bring down my Ph I killed all of my goldfish.  I started out with only adding 1oz of Ph Down with a 5 gal dilution of water from the tank (24 hrs no change), same process but with 3oz only got a .2 change of ph.  Third day I added 6oz of Ph Down with 4 gal of tank water, 2 hrs later I noticed the were dead.  Was it the amount of Ph down I added or was it the change of chemistry that killed my fish.

I'm thinking of getting the Ph exactly were I want it 7.0 and then add 50 or 60 1" gold fish.  Any suggestion or comments would be greatly appreciated.  Don't be in such a hurry to change your water balance.

My condolences-

  By adding the large amount of pH down (6-oz) you may have inadvertently shocked your fish.  You must remember that pH is logerithic.  This means with each "point" of increase/decrease is 10-times acidic or basic than the previous number.  What happened is you didn't allow the fish to adjust to the changes you made.  By adding the 6-oz. on the third day the pH dropped so radically they couldn't adjust quick enough and succumbed.  Don't beat yourself up, these things happen to even the best of us, just chalk it up as a learning experience.  Be happy it didn't happen to some expensive koi or a large school of tilapia.  Keep doing what your plans indicate and lower the pH fishless and see if it remains at that level.  If it does, you are good to go.  If it creeps up, you may need to look at another underlying cause.  I only use a quartzite media, I know this is pH neutral and the only time I have any type of spike is when I find a dead fish and the ammonia spikes

My 175 gal tank has been FISHES for 3 day now so that I can bring my Ph level within limits. My question is can I introduce new fish with these readings?
Ammonia - 1
Nitrite- 5
Nitrates- 160
By the way Happy 4th to all

FISHES should have read  "FISHLESS"


© 2019   Created by Sylvia Bernstein.   Powered by

Badges  |  Report an Issue  |  Terms of Service