Backyard Aquaponics
A place to discuss aquaponics

The expansion is required to keep the current system running.

It will still be run as two seperate systems, the way it is now.

Different power supplies, different timers etc.

Ok its crunch time.

Do I go constantly flooded constant flow, or timed flood and drain? Whats the consensus from the BYAP trials?

Constant = heaps less plumbing, like lots less, very slow flow rate per bed. Ie 10,000 lph divided among 40 odd beds.

F+D = lots of plumbing, but higher flow rates per bed.
??

Constant flow for my 2c !!

Dunno about your massive system but my cf beds run best with a good flow going through them.
The one byap bed I have on cf has a bell in it with no top so the water is drawn from the bottom and it has the best growth of all my beds, and it has a big flow through it.

You could cut down on the plumbing if you run one siphon that controls 10 gb's. 10000lph through 40 gb's is a water change every 4hrs. But constant flooded does not make a complete water change as the water will take the easy way.

Or run both. Have constant flow to all gb's with the main pump. Then run a smaller pump on a spider to push the level in a set of gb's to trigger a siphon. Then at least the gb's will get a flush a couple of times a day. Does not cut down on the plumbing much tho.

I think CF will need higher flow rates than what you propose, turn over a gb once or twice a hour??

Well I would definitely leave the parts of the systems that are running the timed flood and drain with the spiders already as they are since they work and the plumbing is already done.

So, you are wondering if the next batch should get the spider plumbing or not. Well, Creative1 I think once estimated that his successful constant flood system got at least 7-9 lpm per bed. Now that is from memory I can't remember if the number was 7 or 9. But the only constant flood beds I've had run on slower flow rates than that were growing water plants like watercress and water chestnuts that like the still boggy waters. All my other constant flood beds that did well with veggie plants and bananans got much faster flow rates of definitely over 9 liters per minute.

Sorry I don't think in flow rate per hour very well anymore since I started working with the indexing valves I've been converting to flow rate per minute.

I think that you may have to stick with the spider to do it unless you want to buy another pump.

However, one option might be to hook up one system with your original plan of spider valves and the pump for the new section of stuff. And then you might run the second expansion constant flood and compare the two. The system with more constant flood will be a bit more temperature stable. You will probably find out pretty quickly if you need to upsize the pump or if you would rater go back to the original spider plan.

Just a note about constant flood that I've noticed actually any constant inflow bed that gets solids from the fish tank. Remember the old sliming issue of water going over gravel at the single inlet point and needing to poke it with a stick. I've not noticed this issue with any of my timed inflows but it certainly happens in constant inflow in one single inlet location so the money savings by not having to run a separate feed line to each bed from a spider may be somewhat offset by the need for a distrobution grid in each bed.

In your case the fish seems to be the main concern and constant flood gives you the best benefits to water quality.

As far as flow rate goes, I've even left my beds flooded without any pumping for a few days. Plants were fine with it. So a slow flow shouldn't make a difference and would actually help solids drop out into the grow beds. If you find it to be a problem later you could always upgrade the pump.

Thanks for the replies guys, Constant flood seems to be the way to go, anyone got experience in why not? Sliming wont be a problem, no water will be on the surface of the new beds.

Please don't tell me you are going to run the water in under the gravel?!? You won't even be able to see if the roots start growing into the plumbing then!!!! I have seen roots grow into my supply plumbing on constant inflow beds and that was above the surface of the gravel.

So what is the total tank capacity again? How many laguna 16000s do you have? One per tank?

Comon, I have been doing this for a while lol Pics later of how the water enters the beds.

Total tank capacity of 12,500 litres per tank. 2 x Laguna 16000 each tank.




Lets say a pump is providing 10,000 litres at the beds.

Supplying around 40 IBC's

Thats 250 litres per bed per hour. Water capacity of each bed is around 400 litres.

Hmmmm, might be too slow? I'm keen to give it a go if no one says they had major disasters doing this already.

Now I'm curious.

The water may come up from the bottom, but has it come through the bottom of the gravel or just flowed along the top of the gravel then down the media guard pipe to the bottom?