Crazy things forum members do

[Sigidi]

Any ideas on how much electricity one of these set ups uses? I've been thinking of doing it, got heaps of room, but I don't need to be using any more juice at present.

Must say I like the idea though. I wonder if the pumps could be run off solar?

Silent, we are looking at running a 5amp 12v bilge pump (so apparently that's 60w) it was supposed to go on a solar system, but I've found from our local solar guys it is a bit more expensive than I first thought. So I looked at our power bills and worked things out; running the pump on a cycle of 15min on and 45 min off (this allows the growbeds to fill with water, then slowly drain) the pump will run for 6 hours a day and at 60w, that would be 0.36kwh a day, we pay 17c per kwh, so for a weeks running (on the grid our pump) would be 43c.

You can run it off solar if you want, that's why we initially thought of a 12v bilge pump, lots of flow, also runs off 12v solar panels which are topping up a battery and no concerns with blackouts

[silentC]

I have a 100w air pump on our septic system which runs about 8 hours per day and I thought of running it off solar. I contacted our local Solar power retailer and they told me I would need a $5,000 system to run it! It would take me about 100 years to pay it off from the electricity savings

They told me I'd be better to get a grid connect system for the whole house.

What I thought was that you could connect a 12 or 24v pump up to a solar panel and it would just run while the sun was out - with these things it doesn't matter if it runs for 10 hours one day and 2 the next - or I wouldn't have thought so. Apparently it's not that simple - but it seems to work for those solar powered pond pumps.

The panels are still around $1k, which is a lot of electricity.

[Sigidi]

I love the idea. Will have to investigate it for our joint.

Anne-Marie, we found out about it from seeing what Mike (Burnsy) had done at his school and him being gracious enough to answer some questions. Wifey fell in love with the idea as soon as she saw it - she gets veggies without having to remember to water them etc.

There is a heap of stuff to see on you-tube about it, and online generally. I'm sure Mike and Derek would be happy to answer any q's on here (might even get a 'section' on the forum for it?) I'd be more than happy to answer q's, although I'm very new to things. We did just get a book with DVD and CD-ROM from the local library called 'Backyard Aquaponics' by Joel Malcolm, it's got some really great info and the DVD is what has really spurred us on.

[Sigidi]

Silent, we bought our 5w solar panel on ebay for less than $100, we saw a 20w panel at the solar shop for $990, I figure 4x5w panels at $90 (including the postage) makes the 20w of solar a total of $360.

I have to admit I've only done very rudimentary research into the solar thing, but at the rates the chap in town mentioned, it would take us 46 years to break even on the cost of the solar versus paying for the electricity...

I know Carl (aka Weisyboy) just got solar put on at his place using the government grant, might be a way to go?

[silentC]

Heaps of info here (same guy who wrote your book I guess): http://www.backyardaquaponics.com/

They also sell complete systems.

[Sigidi]

Silent, yeah, that is where Mike, Derek and myself spend some time on their forum, a sawg of info regarding all things Aquaponic, so much info...

[derekh]

All my fingerlings came from the same batch, 50mm - 75mm yet there is a big difference in size now. Those fish are about 18months old and had gone through two winters and only one summer. They eat more and grow better in the warmer months.

My fish are now on 4mm sinking pellets but I think they prefer Ridleys 3mm floating pellets. With floating pellets, you can see and hear them hit the pellets hard and make quite a spectacle. Yet, they really don't seem interested when the pellets are sitting on the bottom. I get a lot of waste pellet build-up that I need to clear out and it's not because I over feed. You can also put the occasional lettuce leaf in the pond and it will be gone by morning.

If we get too many people interested in Aquaponics we could beg the moderators for our own sub-forum lol.

cheers
Derek

[Burnsy]

Any ideas on how much electricity one of these set ups uses? I've been thinking of doing it, got heaps of room, but I don't need to be using any more juice at present.

Must say I like the idea though. I wonder if the pumps could be run off solar?

Silent, the school system I have could be run off a 130 watt pump that runs 15 minutes in the hour with water being returned via a 230 watt sump pump that is activated when the sump fills to capacity (I say could be because we just use two 230 watt sump pumps as power saving was not a concern). If you have slope you can set your fish tank high, gravity feed via 90mm pipe to your grow beds which would then gravity to the sump and only run one 130 watt pump with external float switch to return the water - this is the cheapest option if you plan it right.

[derekh]

To create a single pump system, I use raised grow beds and dug my tank into the ground. Water is pumped up to the grow bed via 25mm poly and gravity returns via 40mm pressure pipe on a 15/45 cycle controlled by a $5 timer from B. I use a 25mm standpipe with two 4mm holes surrounded by a 90mm pipe with numerous 12mm holes. The attached pic shows a simple trial system I did for little sis.

The tank is large enough to handle the drop in water level to fill 8 growbeds without troubling the fish. On the rare occasions I have a had a major leak, sufficient water remains to keep the fish alive.

Added pic from early 2008 showing Kang Kong going ballistic.

[pjt]

So, a simple aquaponics system using one pump has plant beds up high, fish tank low and a pump to recycle the water in a closed loop system, there would be need for a top up would there not?
Bath tubs, 44 cut in half, homemade and lined with plastic, manufactured (Reln) tub/pool all would seem to be suitable.
Do the plant beds have soil or is it gravel only?
PS I dont mind my thread being hijacked
Peter.

[derekh]

Peter

I use 10mm or 20mm drainage gravel that has been washed to remove fines. Other suitable media include: expanded clay (best because it's lightweight but expensive), perlite / vermiculite (prone to clogging pump) and coconut fibre (pront to water logging) but definitely NO soil. You need to have media that will promote the bacterial growth and allow for free drainage to avoid root rot. (Some plants don't like AP because it's too wet).

cheers
Derek

[Sigidi]

Peter, sounds like you have the basics squared away and like Derek said - no soil, you even rinse off the soil from your plants before transplanting them into the grow beds.

We've used 10mm blue metal stone, which the boss has mentioned is a bit rough on your hands when is planting out. Also just got a growbed filled with river gravel, still around the 10mm size, but has been through the river a bit so it's rough edges are a bit worn back and apparently much nicer for the boss to plant new stuff in.

The expanded clay Derek is talking about is around $40-$50 per 45l bag, so once you fill a GB which is 2x1x0.3m (600l) you need almost 14 bags or a fistful of $50's:O Although it is the preferred medium for the guys doing this 'professionally' as it is light, but also lets the moisture migrate through the bed well.

[pjt]

Ok so no soil, but more questions...so plant roots just grow and spread out into the gravel?
a 15 on 45 off pump cycle fills grow tubs (with an overflow?) from fish tank then water drains from tubs back to fish tank?
Is the gravel ever removed and cleaned of roots or r they just left there to decompose after the "lettuce" has been harvested?
How matched does the system have to be? no of fish to plants? type of plant ,
I'm just thinking that in a closed loop system the balance of each part has to be very closely matched, How much monitoring/maintaining does the system require?
Just a few ??? I start thinking and then I have to ask the question!
Peter.

[derekh]

The gravel is rarely, if ever removed. I've never needed to do it. I added worms to help keep the gravel cleaner but dead roots are not a problem. There is a preferred ratio but I cannot remember it, the AP website has more info.

I need to top up the water level once a week and sometimes clear my standpipes of roots and leaves. Less than 1 hour a week.

cheers

[Sigidi]

Ok so no soil, but more questions...so plant roots just grow and spread out into the gravel?
a 15 on 45 off pump cycle fills grow tubs (with an overflow?) from fish tank then water drains from tubs back to fish tank?
Is the gravel ever removed and cleaned of roots or r they just left there to decompose after the "lettuce" has been harvested?
How matched does the system have to be? no of fish to plants? type of plant ,
I'm just thinking that in a closed loop system the balance of each part has to be very closely matched, How much monitoring/maintaining does the system require?
Just a few ??? I start thinking and then I have to ask the question!
Peter.

The plant roots do grow bigger and some plants, like mint, just take over if you let them.
You got it with the onff cycle and yep an overflow of some kind to take water out of the bed and drain back to tank, either via a sump tank or just flow back to the FT.
Roots from gravel - you could 'clean a grow bed out between seasons if you wanted, but like Derek said easy enough to have the worm option.
Balancing the system - I was told you need as much GB volume as FT volume, (but not when the system has new, small fish or a small volume of fish) but for maximum bio-mass of fish (around 30-50kg per 1000L of water)the two need to be equal, then the system can sustain itself. Remembering, the plants will only grow as fast as the available ammonia is converted into nitrates and the ammonia will increase over time as the fish volume grows bigger. You do need to carry out weekly water tests to keep an eye on how the system is balanced.
Closed loop - it's not completely closed as the amount of ammonia is determined by total bio-mass of fish, but also by the input of food, less food less ammonia, this can be used when say a large harvest has been done to allow for the lower requirement of nitrate and therefore the lower requirement of ammonia.
Monitoring - the results from weekly 5-7min water tests will give indications of the need to add more growbed, increase feeding, decrease feeding, harvest plants etc.

Peter, go for it with the questions, I can't say I will know all the answers but between Mike and Derek, I'm sure we'll give it a good go