Backyard Aquaponics
A place to discuss aquaponics

Hello,

i'll try to grow tomatoes from seeds in 2/8mm gravel.
I watered manuel and from seeds.
The seeds germinate fine, but the growth is very slow.
The Water is from my 350L Aquarium in which i breed my tilapias.

The Tomatoes should be transplanted in my garden at may.


Do you know why the growth is slow ?


King regards
Dom

Please tell us what your water tests say (pH, ammonia, nitrite, Nitrate) Also, what are the light levels like and what is the temperature. Tell us more about your system and how it operates. It is difficult for us to tell you why your seedlings are growing slowly if we don't know anything about the system or nutrients in that system.

Also, when did you plant them? It is not uncommon for seeds to germinate and then spend some time sending their roots down to get established before the tops start growing again, often has a bit to do with moon phases too. We have been in a period of time for planting root crops so the roots of your seedlings have probably been growing more for the past two weeks. Perhaps if there is plenty of light, the tops will take off for you starting next week.

Hello and thanks for your quick response.
The seeds planted at the 01.03 directly in gravel.
I watered manually twice a day.

The Water has a PH of 6,8 and no² is 0 and no³ 50.
I don't have any ammoniatest here.
Do you think i need some?

System is just a little bit to much, it's only the sole of a mini greenhouse (some of them in which you put your seeds)
It's filled up with gravel, and has some little holes in it, for the drain to run out of the box.

Oh sorry, the box stands directly at the southside window of my room, and gets a lot of light the last days.
The Tomatoes has their first leaves. Not the seed leaves !

Dom

Welcome Dom!

Since it's not a recirculating system I am not too sure, but I would guess if you wait another month they should get big enough. Watering twice a day should be OK as long as they are not flooded and not drying out.

How big is your gravel? Can you post a picture?

I think the flood/drain effect would give your plants far more nutrients than simply watering twice a day, so they may be stunted by lack of nitrates, iron, etc. If your tomatoes were in soil they would do fine with watering once a day or so, but in gravel they might need far more.

So they have been in just over a month and your are basically watering the seedlings with fish tank water that already has a proper filtration system. In the gravel, perhaps watering a bit more often would help. Perhaps also adding a bit of sea weed emulsion might give them trace minterals they might be missing but it will also tint your fish tank water brown if you do.

It sounds like the tray of gravel is really small and it is all brand new. Most aquaponic systems require about 6 months to really mature and take off but such a small tray for the seedlings is probably not going to give you spectacular results. However, I expect the seedlings to take off a bit starting next week as the moon phase comes back around to above ground growth.

Hello here you have two pictures from my Tomatos.
The first is from 27.3 und the second from today in the evening (9pm)
So the leaves go up in the evening, and down in the morning.

The hole in the bottom of the box is very small 4mm, so the water stands like ebb/flow in the box.
When i put the stones from the surface by side, the other stones seems not wet but moisty.

When i look at the pictures it seems not so bad, as i belive it tomorrow :-)
The humon forget the state of growth very quick :-)

P.S.: Sorry about my bad english, i'm from German.


Dom

I'll watered more than twice a day, do you think that the seedlings seems ok ?
Or should i change something else ?

Dom

They look okay to me.

I planted some tomato seeds a couple weeks back and they have been very slow to get going. My system is new and other parameters are okay... The only reason I am not worried about the little seedlings (much like yours) is that at the same time I put three tomato plants in that were 10-12 cm tall and now they are 35 cm or so... I'm just guessing it takes the seeds a little more time to establish and get going.

I will bet that with in a couple weeks you will have to thin those out and pull half of them to make room for the others...

Keep us posted with pics!!

CB

Hey CB,

thanks for your pleasant post.
I think you're right with the collecting time for the seedling to gets their roots.
Last year i seed in cocos and so i can remember the growth was faster than in gravel this year.
But when the starts with quck growing in a couple of weeks, so thats ok.
It's my first aquaponic project, so i don't want to leave plants or fish.

How much fish do you'll give on 1000L.
It's Tilapia which can grow to 1200g max.
So i think 50 fish in 1000L Water, and 2x500L Growbeds should be fine, isn't it ?

P.S.: I hope you understand my english

Dom

Even with Tilapia, I would recommend you only stock 30 fish for the first 6 months while your system matures... and you gain more knowledge...

The empty System in the garden is still running, with 10% of aquariumwater, but without fish.
I'll give the fish at the middle or end of april in the tank.
The Systems runs only from April to Octobre, after that the pumps stops and the fish leaves the tank.
Plant will be harvested.
We have a cold winter, so there is no chance, that the bakterias survive.


Dom

Which suggests that you'll be recycling the system when you put your fish in...

All the more reason to keep your numbers down... and your feed rate, until cycled...

Keeping your numbers down... will also enable you to feed to maximum rates later... without stressing your filtration beyond capacity..

Hmm it's seems a little bit less fish for 1000L and 1000L substrat (2t gravel).
But you're right that it's possible that the fish can grow out to fullgrown with max feed rates.
How much fish do you have in your system, and which size has it ?

I think some bacteria may survive and would be interested to hear how long it takes to cycle again. You could get a head start by adding pure ammonia, ammonium chloride, or urea to get it cycled when it is still too cold for tilapia.

Let's see if I can get a decent translation to Deutch......no luck. I translate back to English and get pretty poor results. (like this: Ich denke, einige Bakterien können überleben und wäre daran interessiert zu hören, wie lange es dauert Zyklus erneut. Sie konnten einen Vorsprung, indem reines Ammoniak, Ammoniumchlorid, Harnstoff oder get get es radelte, wenn es noch zu kalt für Tilapia.) I had hoped for better...