Told you I'm into pushing the system. Actually it is 40 tilapia. I have some communications from a place that does low density AP that stated that they consider the lower limit of fish weight to bed area ratio to be 450 grams of fish per meter square of raft. Well I've got around 10 kg's of fish max and 4 m2 of gravel bed (over 2 kg's per m2). Somewhere things are not adding up......then again they did not say whay they planted in those rafts.
Harold Sukhbir said:Three cucumbers, 12 strawberries, 5 tomatoes, 3 corns, 2 kale, 2 butternut, a pile of spring onion and water cress, cut flowers, spinach, parsley, lettuce................................................
And how much Tilapia?.........probably 100? because you might need that amount. Sounds like it's commercial....no wonder you're nutrient deficient!
Kobus Jooste said:
Hi Moe. These guys are all giving you great advice. I'd like to put in my vote that I think it is most likely primarly #3, which is causing stress that may be making the plant more susceptible to disease and unable to properly uptake nutrients. In soil you typically wouldn't plant tomatoes until late spring when the soil temps are no lower than 15c, and then you should expect very slow growth. Given that this is a trout system I might even make the bold, but unfortunate, assertion that you should avoid "summer" crops all together and focus on cool-weather, "spring/fall" crops like snow peas, snap peas, greens, broccoli, etc. Is the second system going to have warm water fish?
Thank you everyone for your help. Just to update on what happened to my tomatoes. The first batch just started good but then the new growth became yellow and stunted and the whole plant slowly slowly bleached. The same happened with the second batch but the miracle happened with the third batch and it started growing pretty good with lush green leaves and is growing lot faster than my potted tomatoes. Now the things that i have tried and did work for me, so i wanted to update everybody incase somebody has the same issue with tomatoes in the start.
1. Do you think it is happening because my growbed is not mature ?
This definately effects the growth of tomatoes as i build two systems for experiment sake and the new system is still having trouble with tomatoes but the older one which is almost 3 months now has started getting good growth
2. Or my Growbed not deep enough
I didn't change the depth of my growbed so at this point that was not effecting the growth of tomatoes.
3. May be because of the water being cold as it is 15C ( i don't know if tomatoes like warm water)
This definately was another thing as i put trout in my new system and bought some tropical fish from petstore for experiment sake and raised the water temp to 24C and it did help a lot not only with tomatoes but pepper and eggplants as well which are now flowering
4. Or My flood and drain cycle being too quick
Flood and drain cycle is still the same so that had nothing to do with tomatoes not growing
5. Or is it Damping off disease
6. Or is it some kind of nutrient deficiency
Ok this one is very important as i found that due to my high stocking density my system tends to drift down to ph 6.5 and i was adding hydrated lime to bring it up but in the last four weeks i didn't do that instead added crushed eggshells and let the system run at PH of 6.6 and i didn't have to add anything to the system.
So in my experience with tomatoes three things are very important
1. Water temperature
2. PH ideal 6.5-6.9
3. System Maturity
In my newer system the PH is 7.6 which iam trying to bring down to 6.9 over a period of four days. Once it is at 6.9 i will plant a batch of tomatoes in the newer system to see how they will do and keep u guys posted on that progress.
Another thing as i wasn't able to get MaxiCrop here, i used another brand which is available in Local Hydroponics stores in Canada called " Mermix Seaweed" and is fish safe and healthy. I have used it with goldfish, bluegill and trout. Thank you all once again and i know iam new to aquaponics but still wanted to update what i have found useful till now.
Cool thanks for the update.
Yes I think water temp is probably a major reason many of those plants you listed are doing better since toms, eggplant, and peppers are all warm season or even tropical plants.
You may find that salad greens, and many cool weather crops will do better with the trout system. Broccoli, cabbage, kale, kohlrabi, collards, peas, lettuce, beets, turnips, radish, carrots, and many more will do fine with cooler water once they get going.
Oh, and thank you for sharing the brand name of the sea weed available in Canada, I'm sure it will help others.
Yep, again Moe, I think you know exactly what is going on. Temperature is a big one. Should be closer to 20 - 25c for plants you typically grow in mid-summer. The other big factor here is the age of your beds. Your bacteria colonies will build up over time and release more and more nutrients. I wouldn't expect to see really good tomato growth until about 6 months. Because your system is so cold that is slowing down the development of your bacteria colonies even more. Because of the huge root systems tomato plants develop they will ultimately be happiest in a bed that is at least 12" deep.
Let me know if you would like us to ship MaxiCrop to you.
Yep,have to agree with Silvia on the question of maturity.I've had the same experience,after 3 attempts, tomato plants are finally growing approx. 4 months into maturity of the system.These last tomatoes are growing way faster and stronger than the previous set.I've also supplemented with boron and molybdenum as tomatoes requirements are on the low side in our fish feed. I have a friend who runs water like a river(flooded) in long ground troughs, his Ph is about 7--7.5, his beds are a couple years old and he has amazing growth, and they say tomatoes don't like wet feet!,so i think maturity is definitely a factor. As i live in the tropics i am unable to comment on effects of water temps below 65 F. Thanks for sharing info on your progress.
Just thinking out loud. Do you heat your system at all?
Live plant aquariums use under-gravel heating cables to stimulate convection currents through the gravel to prevent anaerobic conditions. The idea is that you gotta heat a tank anyhow, so why not in a way that it helps keep the plant roots healthy.
Maybe if you do any heating you do to your water in the grow beds around the tomatoes, you will create a warmer micro-climate around the tomato's roots.
Sylvia Bernstein said:
Yep, again Moe, I think you know exactly what is going on. Temperature is a big one. Should be closer to 20 - 25c for plants you typically grow in mid-summer. [snip]