Backyard Aquaponics
A place to discuss aquaponics

I've set up a new system in our new house after running a couple of systems at our old place a few years ago.

I'm struggling to keep any plants alive in this new system and am stumped as to what I'm doing wrong.

At present it doesn't have any fish as it's cycling, with my previous systems the plants never dies off like these are doing.

Any thoughts or suggestions are welcomed.

So far I've managed to kill Bok Choi, Strawberries, Tomatoes, Beans, and Chillies.

The ph was a bit high and it is dropping, I was a bit worried it could be my expanded clay but that seems unlikely.


The water has had SeaSol added to the fish tank and I've hand watered with SeaSol about every 10 days.


Could it be a simple nutrient deficiency?

Water level in the grow bed?

How are you transplanting the plants?

Sorry to see your having plant problems Viktor.

I may just be seeing the aftermath but it looks like leaf scorch to me.

What type of Seasol are you using? When you watered with it did you get any on the leaves?

Sometimes this can be bacterial but my gut tells me that since there are several different types of plants it's probably environmental. The plants look like they were losing more water than they could move up the stem and replace. Sometimes this can be caused by wind, low humidity, high temps (with high temps it's usually more on curved leaf surfaces than the whole leaf), roots that aren't well established would make it more likely I think. Fertilizer burn can also cause this sort of thing which is why I asked about the Seasol. Make sure the plants are hardened off to the conditions they will face in the grow bed before transplanting. The plants might be getting too much light, giving them a bit of shade till they are established and then gradually letting them adjust might be a good bet.

I have considered this, they were all set to 35mm below the top of the expanded clay. This was partially done to stop the clay floating. I've changed the one with the beans to 25mm and the clay is floating a bit again.

I'm considering taking some clay out and putting a layer of river gravel over the top of the gro bed to stop the floating.

My previous systems were done with river gravel mostly.




I'm washing all of the potting mix/growing medium off the seedlings before transplanting them into the grow beds.




I've also considered this as we are still getting to low 30's during the day with the beds being in full sun from early morning until dusk.



Just what I'd call their 'normal' Seasol - http://www.seasol.com.au/products/61/Seasol

When watering I'm using a small water can to water around the base of the plant.



Thanks, I might have to play around with the grow bed height and put some sort of sun shade up as well. The temps certainly don't slacken off much.

I should also have mentioned that I've had the timers set to turn off at 7pm until 6am. I was doing this to be considerate to my neighbours. Maybe I need to keep it running 24/7. I didn't think this would cause me any problems.

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The first thing would be to carefully remove the clay from around a plant and see if it's roots are in or above the wet zone..

I would assume such a desiccating death would be wrong water level..

and you don't have too much salt, do you..

PS - I would turn those T feeds to vertical, and add a short length up and down so the clay does not get wet and start algae accumulation..
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+1

seems pretty shallow - particularly if a constant flood. [ but then have seen other systems here that are wet].

usually when new seedlings added I have water about 5cm and give a hand water with just water (from FT) for the first week just to keep them happy. New plants really need to get some decent root zone (depth) and root aeration.

+1 regarding shade - try some 50% shadecloth. Sunlight can dry out quite rapidly.

Q. also hard to say from pictures - but are the problems all in one part of the GB ?
(looks like some are OK but some are not).


re: delivery - I find with single point water delivery that there can be quite a bit of variability across GB, though lots of people do it. I prefer to add water via a PVC pipe with holes so water enters at many locations.

what happens at night when you shut down ? Constant flood ? May be better to drop level a bit. Can do this by putting a small hole in your standpipe to dribble water level down a bit - less water stress at night and bed will stay damp.


also is the 90mm pipe your standpipe ? Probably better to have inflow as far away from outflow as possible (will affect later when plants larger). You could simply extend PVC across the bed if that is case.

Hi Tony,

As mentioned, elbows or distribution runs on the inlets will help reduce algae in the grow beds. This might also reduce the splashing sounds for the neighbors. I worry more about air pumps, most people don't mind the sound of splashing water. I'd probably run 24/7 but when the fish are small sometimes you can get away with shutting it down at night to save on costs.

If you're doing Flood and Drain with siphons or have an over sized sump and are doing CF but turning the water off at night then the hole is a good idea - just so long as you have capacity in the sump to hold the water that drains there. Many people run CF because they just want a small sump so not putting the hole in helps keep the sump size down. If you can't put a hole in the pipe and you are running Constant Flood then it should be on 24/7 in my opinion.

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and I now realise it is constant flood, so it should be easy to determine the normal water height..

CF is (as noted already) not ideal for single point entry.. Nutrients will flow from entry to exit.. distance of least resistance..
I would either convert to either Syphon or timed flood and have small holes at the base of the standpipe..

You say it is still cycling.. How.. What nutrient is going in to expand the bacteria.. I hope you take a walk each night for a wizz..
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Not sure it's CF BuiDoi but I don't think it will matter for this problem unless the plants are standing in water that isn't flowing overnight. Don't forget that nutrients also diffuse through the water in the bed, it's not just about flow.

The system is a flood and drain using auto-syhons with the water in constant flow.

So it's a slowish fill with a fast drain cycle.

I've since taken the time off and put two longer stand pipes in the 2 larger beds. My next step is to remove some beads to get the height better. Then I'll try some more plants.

Haven't added any urine to the system, I did going down the peeponics route with my first one. I think the second one had some water transferred over from the first one to kick it off.

May have to rectify that with this one.

My wife has raised the idea that it may be water quality, after Tropical Cyclone Marcia the local council had major issues with both water flow and water quality. Staring to wonder what they've done as some of our other plants are showing signs of distress yet we water regularly.

The only plant that hasn't died is the lemongrass.

I find re-setting the flow height is now making the expanded clay float again. I'm going to remove around 100-150mm and put in some 20mm river gravel. This is what my previous systems had for grow media so I'll go with what I know.

If this still doesn't produce results I'll changes from auto siphons to a basic flood and drain system.

Need to add some fish as well.

Try some direct seeding in beds, and cover/protect from afternoon sun with some shade cloth. Looks like sunburn/scorching to me.

Nutrients aren't suspended in the watet.. but are dissolved.. so aren't affected much by channeling.. once the entire bed is flooded the nutrients will be eventually spread out evenly throughout the bed by diffusion.. secondly uptake of water by the plants also acts as a means of water movements in the GB.. because any water removed from around the plant roots must be replaced.. and hence the replacement brings new nutrients to the root zone.