Backyard Aquaponics
A place to discuss aquaponics

Several things have been prompting me to wonder about using beds then removing them from the active system, to work as solids-containing dirt (gravel) beds. I wonder if you could gradually fill you yard with both online and offline gravel beds, all growing plants? In a way the AP system could leave a trail as beds were taken offline and became "dirt" gardens.

One reason I wonder this is that stray seeds started growing in the gravel pile from the my system from two years ago. There are surely many nutrients in the dried out solids in that gravel that would make some less water-loving plants happy? Another is the build up of solids that has happened in my beds because I don't have plants in them, and VB cleaning his gravel and getting solids and worms from them. Maybe those beds could be taken offline just become dumb planters?

EXACLTLY ,, my conclusions revolve around gravel beds being a pian in the behind as we are trying to compromise their true benefit ,, they are in reality a bio-filter ,, some just choose to put plants in the top of them. First problem dust/ sediment ,, I';m not willing to wash tonnes of it ,, buy from supplier after several days of rain, ask for it to be shovelled from mis or high on pile. First problem solved ( well lessened).
Now for the actual gravel beds ,, I read you all pumnp your fish tank water straight in ,, solids and all ,, well , we read about what people go through when emptying out,, it's obviously not a good thing.I feel that these gravel grow beds are principally a micro-organism filter and as such have limited abilities to cope with solids. Add worms , some say ,, but then we read about dead worm rotting smells etc , I suggest either we remove these solids before or during the micro-organism/ gravel filter.
Sock or bag type filters before the grow bed will do the job. But if we have these gravel bed's for gross feeders , corn etc , we want all the nurients wer can get ,, so time for compromise. the floor od the gravel bed should be wwwwww shaped with flat stainless steel perforated metal on top of the wwwwww.Totaly insoluble solids??? , you know what I mean ,, will find their way down into the v bottom and can easily be romoved. No gravel cleaning needed and rich water for plants. The nurient rich water from this filter/grow bed is then ideal for over-flow into a floating raft system.

I could be wrong , I may be wrong ,, you guys can please tell me what is wrong?

My 2 cents worth my whole system runs fish water from 2 tanks 2000 litre to 4 grow beds and all the other beds[4 and other tanks ponds and nft run on filtered water i also think the worms are good because they make worm juce that adds neutrient to the system

OK Chappo, your wrong.....

I have not had any problems at all with solids in my beds and the system has been in production for many years now.

i think this could be possible if your main aim was growing plants but for most it is a combination of both that people are aiming for. What is the point of having the beds off line, why not just continue to pump through them, if you want a dirt garden there are cheaper ways to do it than to build the bed first, fill it will gravel and then to run it as a filter and then turn it off.

on the subject of washing and emptying gravel beds e.g VB, he was running a large number of fish on just one bed so it can be expected that he has a large amount of build up, but the thing is he had the worms feeding off of it and the plants were really booming. He had a dead worm smell because he interrupted the cycle and smashed all of the worms into mush while cleaning the gravel for the new bed. I am sure if you ask him now the smell would have completely gone because the system would have broken it all down into nutrients for the plants to utilize.

I never plan on washing my gravel. i did not wash it before it went in the beds and even if a have to move i will not wash it. any way I think you might be moving away from the idea of aquaponics, which is fair and reasonable but not my plan.

IMHO Nick

You are rite joel [note edit

+1

It must be remembered that the only reason that I had cause to clean the solids out of my bed was that I was moving all the gravel and thought it a good idea to do at the same time. If not for that, the solids would have remained and were causing no issues - given that they were no doubt no longer decaying. Gravel beds are fantastic filters, hence the build up of solids. Al those with gravel beds would know and agree that although you will end up with some very dirty water in any hole you dig in your bed on the flood cycle, the water that is coming out of the bed into the sump or fish tank (depending upon your layout) is very clean. This is the breaty of the whole system. The grow-beds have more than just nitrate rich water in them, they are a whole ecosystem that supports plants extraordinarily well. Some of these solids inevitably find their way out of the beds, but will equally find their way back again if going to the fish tank. With my system, in which I drain the beds to a big sump via autosiphon and have a relativelly low volume (say 2 or thousand litres per hour at the head that I have) pump in the sump continuously pumping to the fish tank, some solids will build up in the sump in areas where the siphon action is not stiring them up, but this is all good because they can be removed easilly. Therefore solids will either be in the sump or the grow-bed and not in the fish tank - a good thing.

The only reason why I have been thinking of adding a swirl filter to remove some (and I repeat, some) solids, is that I am a bit short on grow-beds presently for the density of fish that I have and want to remove some of the poo before it converts to ammonia. If I had ample beds, I would not even give it a second thought.

Although it is heavy as shit and a pain to clean at the outset, I am a massive fan of gravel and this has been reinforced to me by the great job that my new gravel bed on the barra system is doing.

Can't add much to that.... if we only wanted a bio-filter then that's what we'd all run....

But we WANT the solids... they provide/supplement the trace elements for vegetative growth... the worms help this process....

They are in effect duplicating a natural sequence/system.... just that the gravel isn't in a pile on the ground ... it's elevated in a growbed....

No reason you couldn't use old growbeds as the basis for "normal" style gardens... or even build new ones for the purpose....

Just that eventually, like all soil based systems..... you'll exhaust the nutrients/minerals contained in the growbed and have to supplement/fertilise....

I figure just keep them on-line and let the AP system do that automatically and constantly

the only time i have had an issue with clogging is in the two (or more) years of using a 200L grow bed to 'filter' 30 or 40 KG's of fish over that time..............

obviously very under rated grow bed wise.

if you maintain the growbed ratios AS SUGGESTED i dont think anyone has had a problem!

and just 'cause you pull out a root ball with sweet smelling brown 'residuals' doesn't mean a thing.

Experiment away, please, but there is wisdom not preaching on topics that some people have been PRACTISING for a few years.



Steve

Thanks guy's,,now I know why I'm wrong , so can get my thinking back onto correct path.

Well, regardless my outside beds go offline or nearly so in the Wintertime anyway (that is one of the reasons I am thinking along these lines). I can't run them year-round. Maybe while it is too cold to keep them hooked up they can be of some use with growing cold tolerant plants. It would be interesting to see how far one fish tank's water could stretch, i.e. more beds watered less frequently.

One of the other reasons for thinking this was repotting my office plants with the goo cleaned from the beds; I think my office plants appreciate this.




Chappo that's exactly the thing I have been mocking up in my thread:
viewtopic.php?p=111439#p111439

The downsides of this might outweigh the upsides, don't know yet.

dont know how you'd go with nitrogen levels, but i bet ya if you set up a small pump recirculating water though it and used water yout of it for manual watering of dirt plants they would appreciate and leaching from the solids and/or worm castings

I am not advocating using non-gravel filters, let's get that out of the way please.

Nick said that you might want to do this if you were wanting to be plant-heavy. My thinking is that you would want to do this if you wanted to be fish-heavy. I.e. saturate a gravel bed with solids until it wasn't filtering well anymore, then move to a new bed and let the old one break down and support plants using rainwater only. Kind of a scorched earth policy heehee. When the offline bed starts slowing down (like months later) hook it up again.

Like I said, multiple reasons for thinking this. Aren't there some crops that would like drying out a bit after the initial growth and flowering?