Backyard Aquaponics
A place to discuss aquaponics

Hi, I have a CIFT PIST system that has been growing well for a few months. My problem is that in the last month I have had lots of growth but very little production. My tomatoes were producing well until a few weeks ago but now they are still flowering but not setting fruit. My pole beans are getting to be about 6 feet high but no flowers or beans. Any ideas? It has been very hot. Here in South Florida we normally can't grow vegies between June and September because of the heat.

Have you tried putting some banana (w/o peel) into your growbeds? One of the nutrients that tends to be missing in younger systems is potassium which can affect your flowering & fruiting. Adding banana is an organic way to add the potassium. I have blue barrel half beds and use 1/2 banana per bed when I think of it. I've read here that monthly works well.

Welcome six, a photo or two of the plants wouldnt go astray, can usually tell what is missing by looking.

It does sound like potassium is missing, but what is your PH?

A dose of Maxicrop Seaweed fertilizer can help.

The problem could be either a lack of potassium or the heat or both. I'm still getting flowers and fruit from my tomato plants but they have been going strong for months, the plants that are newer in the system are not flowering yet.

Anyway, they do say that heat can reduce or stop flower/fruit set in tomatoes. I don't know about beans as much as they don't seem to like growing in my system so far.

Potassium can be as simple as some banana in the grow beds as the others have stated. Maxicrop seawead plus Iron is an option here in the US for both Iron and potassium supplementation. Since I haven't gotten any yet, I've been using Iron Sulfate and Potassium chloride in the system. Another option I'm looking into for Iron/potassium supplementation is greensand.

As people noted, the pH of the system could have an effect on the plant's use of nutrients.

Thanks for all the advice. My ph is a little higher than I would like at 7.5 but I am reluctant to add anything containing iron because we already have high iron levels in our water naturally. I will try the thing with the bananas though. After all I just had a whole hand of bananas ripen this week so I am swimming in free bananas anyway, I just have to pry them away from the kids.

That PH is ideal.

wait till the plants start showing you they need iron before adding any then. They show you this by growing new leaves that are yellow with green veins.

A pH of 7.5 is not bad so long as your plants are not showing signs of iron deficiency. Most people have the challenge of keeping their pH up since AP systems tend to drop in pH.

Sixbubbas your problem is simple. It's way too hot in Florida to grow tomatoes in the summer. They don't like to set about 85 degrees. I had that same problem and asked one of our resident guru's Tom Macubin if there was something I could do. He said to be patient until the fall....

I am trying an experiment of misting my plants a couple times a day to see if a little cooling will help but I suspect not.

I guess the good news is that by the time these plants are able to set fruit in October, they'll be huge and will produce a lot very quickly.

Jazzplayermark, do you have any suggestions for what will do well here in Florida during the summer? Should I just stick to lettuces and other green until it cools off a bit?

It's been a mixed bag for me but this is my 1st year trying to grow here.
The things that I've had good success with in my AP system:
basil
lemongrass
bush beans
mint
cuttings from hibiscus shrubs

The things that have failed for me are:
parsley
oregano
cilantro
tomatoes: lots of grow and flowers but no fruit.
pole beans: made a jungle but not a flower.
spinach: lots of growth but never flowered
lettuce

Keep in mind that it is VERY hot in my greenhouse ( I WILL have some kind of evaporative cooling before next summer).

Currently I have about 15 or so tomatoe plants that are looking really good in terms of growth. I'm hoping that when it finally cools enough they'll be so big that they'll produce tons of fruit.

I wish I had built my greenhouse such that I could have removed some of the plastic and just had screen to allow for more air flow. Perhaps that'll be a good winter project to get ready for next summer.

Sorry I didn't mean to type spinach. I had it on my mind.... I meant brocolli had lots of growth but no flowers(food).

It is also my first year growing AP, my system pH is kinda high due to my use of shells as a large % of my growbed media. I've had issues with Iron deficiency due to my pH of 7.6 + but I think I'm finally learning how much iron I need to add but I don't want to overdo.
So far in this heat (my system is under some shade but no greenhouse so cooler than Jazz) my cherry and grape tomatoes are doing ok and the basil is fine in the heat. My Okra had been doing poorly for a long time but seems better now that I've been adding more iron. I have some crowder pea seedlings just comming up no so I hope they do better than the beans did for me. I have stevia doing ok as well as aloe and a few other odd things in doing ok but not great. I'm now testing sweet potato in some beds but I need to be careful that the growing tubers don't bust my grow beds open. Mint is also doing ok but I only grow that in small beds to keep in contained.

Back in the cooler weather there were plenty of other things to grow. Broccoli likes the cooler weather I think as does kale and they would have done better for me had I been adding enough iron and potassium. Lettuce did great!!!!! Onions did well. And parsley was just fine in cooler weather, Most of my parsley has died off now in the heat.

My system is outside with a fair amount of shade especially over the tanks but it is very hot here. We had no trouble in May and June but once July came everything quit flowering. I agree that it is just too hot. I have had some luck with other things though. I have a small carambola tree which is doing well, pineapple has grown quickly and I have successfully rooted and transplanted out some hibiscus cutting and even some cuttings from a citrus rootstock that are ready to be transplanted into the ground in preparation for grafting.
I would like to raise my potassium levels though TCLynx, what do use to supplement?

for a while I had used a potassium supplement I got from Aquatic Eco Systems but that ran out and they arn't selling separate nutrients like that anymore so I have lately been using small amounts of potassium chloride (murate of potash.) The murate of potash seems to work but I don't know if there might be too much build up of chloride over long term. I have ordered greensand that will help with both iron and potassium but it is on backorder. I think I will go for maxicrop with Iron once i get around to getting some that will take care of both iron and potassium as well as micronutrients.

Does anyone know anything about potassium permanganate? I know that in very small doses it can be used to treat ich, but would it cause problems in doses high enough to raise the potassium levels for the plants? It is easily available in my area because most homes use it to remove iron and sulfur from the well water.