Backyard Aquaponics
A place to discuss aquaponics

Hi Jeol

I have set up a continuous flow system, pumping water from my tank through to 2 fibreglass tubs. Water is flowing very well, but right through to the bottom of the tanks and out the drain pipe back to the fish tank. Problem is the water flows without dispersing to parts of the grow bed - just a simple case of flowing in and out - and a very dry grow bed.

Do you have any suggestions?

Much appreciated.

Brad, Cairns

G'day Brad,

There's two ways you can deal with this. Firstly, if you want to keep the whole system as a continuous flow, you might need to look at creating more of an irrigation grid across the top of the grow beds, dispersing the water more evenly over the top of the gravel. I have one of my systems that works this way and originally I didn't disperse the water over the gravel well enough and most of the bed was useless dry gravel. Plants were only planted next to the pipe that dispersed the water. Since then I have adapted it with extra pipe work on the gravel to disperse the water more widely. This bed now works beautifully..

The other way to deal with it is to create a flood and drain action in your beds, this can be done by using a couple of methods. The most simple method is to create an automated syphon much like those used in barrel systems, check out Baldcats picture under the 'barrel ponics' discussion. They have created a large loop in the return line from the grow bed to the fish tank, the water fills up in the grow bed to the height of the loop, then starts the syphon, and and all of the water drains out..

You could also use a timer on your pump. Slow the flow of water out of your grow beds enough that they will fill up slowly, being sure that you have an overflow so that when the beds are full excess water will just flow out back to the fish, your pump can then switch off and on at intervals... It's quite difficult to explain in words...

Personally I would go for the automated syphon, or extra irrigation over the gravel surface..

Joel

Thanks for that Joel, I think I will try the syphon method as placing more 25mm pvc over the grow bed takes up a lot of space. My 2 grow beds are each about 600 by 900, with about 200 of gravel. For interest, I'll send you a picture when it is finished, it is not big, but hopefully enough for me to grow my own herbs and veges, and stop getting cranky eveytime I see wilted broccoli at Coles for $7.50 a kilo!!!!...Cheers, Brad

Great Brad.... What are the fibreglass tubs that your using for growbeds, are they something that had a previous use and you've adapted them..

Please do send me some pictures just for my own information, but also, if your agreeable I'd like to put a collection of photos of different peoples systems here on the board.. It's great to get an idea of the defferent ways people are designing and adapting systems to materials on hand etc..

Joel

Can't remember what the tubs were for, my brother in law is a fibreglasser, and he may have made them foy wife to grow herbs??? Anyway, they have been sitting around for a while - same with the round firbreglass fish tank, it is about 400 high and 1.4 m across.

Still not sure how the syphon thig works yet - maybe my drain hole is too big, it is a 50mm hole in the bottom of the tank with a drain pipe running back to the fish tank - when the pump is on, it gushes through the pipe. I have been sitting here all afternoon thinking how to make the water fill up to the top, then drain out, or fill up quicker than it drains out.....keep experimenting I guess.

You could do it quite simply with a timer on the pump and a stand pipe like I use in my flood and drain system.... Did you have my book with the details of how the standpipe in the growbeds work?

Hi Joel

I remember reading about the standpipe, but it didn't click with me.....Drrrr

Before I do anything, let me make sure I am clear about it. A 40mm PVC pipe fits into a standard 50mm shower drain plug. This plug has a small hole cut out in the centre and is fixed into the drain pipe. The standpipe then has 2 6mm holes drilled at the bottom. This will mean water can only get down the drain via the 2 holes until it reaches the top of the standpipe which is cut with a V shape at just under the level of the gravel (so that water doesn't go above gravel level and cause algae) and the water will then flow through the top of the pipe and down into the insertion made in the plug.

The gravel won't fall into the standpipe through the V cut?????

Also, I am not sure where does the timer fit into all this?

If this is all correct, I will need to repalce the grates I am using as a drain because I cannot put a plug in it.

Is this right?

Are you sure you wanted to start this forum with all these questions??

Cheers
Brad

Yep, that is pretty much it Brad, but I think the stand pipe is 25mm and fits just inside the lip of the plug, this whole bit fits inside an outer pipe..... Woah, hang on, this is all getting a little confusing, do you have a DVD player? Watch the DVD segment on the flood and drain system, it explain and show the standpipe in that.. The same video segment is also on the CDrom, just not as good quality, hopefully this should help...

Then if you get one of those times that you set to go on for 15 mins, then off for 15 mins as it drains, then back on again etc... You can be flooding the bed and draining the bed as the pump turns on and off...

Don't know if I've explained it clearly, but it will work....

Cheers mate, will let you know tommorrow how it went........

Hi Joel

I was able to use a 40mm drain pipe, with a 25mm PVS insertion - what a great idea - it works like a charm.

One problem I have now though is one tank fills faster than the other, so after making sure the pump speed doesn't overflow the faster flowing tank, the other tank misses out of the water, its only coming up about half way.

I am assuming that there is a little uneveness, and if I jack up the faster flowing tank, the problem should sort it iself out.

I haven't tested it yet as I have spent the day cleaning eveything up in readiness for a cyclone hitting tonight.

Do you think jacking up the faster tank will fix the problem.....if so, when I get back from my next trip away, the fish will be just about ready to go!!!!

This aquaponics thing is a good diversion from my normal working weekends!!

Cheers
Brad

I guess you can deal with the differnt fill rates in two ways, put a valve just before each grow bed so that you can adjust the flow going to each one.. Or, ad a leveling pipe hooked into both tanks... Theres an exqample of how this is done in Travis's barrel ponics manual, you can download it from the barrelponics topic..

Good luck with it Brad, hope the cyclone isn't to bad.
Joel

Hi Joel, I have a fibreglass tank and was wondering best way to keep the bottom clean of dirt etc

Nice one Brad, Keeping the bottom of a tank clean is a great subject and could be quite indepth, covering many different methods, so I've started it as a seperate subject...