Backyard Aquaponics
A place to discuss aquaponics

Greetings all. I have just hooked up the plumbing and have run my pump. It takes about 7 minutes to fill the flush tank, 2 minutes 30 seconds to empty into the grow beds and then about 6 minutes for the grow beds to drain. Are there guidelines that I should be using for Barrelponics? I feel like the grow beds are draining too quickly. What the range that it should take the grow beds to drain? Thanks.


Brett

What's a flush tank?

I had a similarly short flood and drain cycle on my single barrel system and it worked ok

It's the tank that sits above the grow beds in the traditional Travis Hughey Barrelponics system. Thanks for the quick reply.

The general rule of thumb is turning the FT volume over every hour but that is a very broad recommendation. With mini systems like yours Id prefer a trial and error method as the volumes are so much smaller. Watch your system behaviour like water quality, parameters, fish health, plant growth etc etc. e.g. If the water is cloudy from particles your GB retention time is probably too quick (that is if your stocked correctly).

I think you will benefit from slowing it more than you have now.

Thanks. Is the only way to do that, by using a timer for my pump and restricting the drain to lengthen the times?

I agree with Charlie. >> think you will benefit from slowing it more than you have now.

However ultimately in some system designs flush time is secondary to whether the media and roots stay wet.
You need wetness in the media - may be OK for clay but might be an issue for rock media/scoria.

You could make the flush tank redundant and just feed the grow bed and then timer off to drain.
wouldn't bother with a siphon in a small setup.

you could go with a standpipe with a small hole for draining.
(maybe your current setup allows for that ?)

you could also use a ball vale at the outflow but they might tend to clog up over time.
else maybe put a cap on the lower outflow and drill some holes in it instead so less water comes out and drain time is longer.

[edit] after looking at the pic below - if yours looks like that - then why not join the two bottom drain pipes to a 'T' and then put a ball valve on that - that would slow it down. You have the overflow outlets as protection anyway.


**** for those interested in what a 'Travis Hughey Barrelponics' looks like.
http://www.aces.edu/dept/fisheries/educ ... ponics.pdf

[edit] and added a pic below

here is a pic.


p.s. on page 42 of that doc (where the pic comes from) it says

"The 10”long tubes can be cut short at this time if you wish. They should be
left at least 6” long as they are the lowest part of the siphon for the growbeds.
Cut the 3” section of 3/8” vinyl tubing in half and insert one piece into each of the
growbed downspouts to restrict the outflow of the growbeds. This helps the
water from the flood tank stay in the growbeds for a little longer than with the
pipes alone. It gives the plants and bacteria in the system more of a chance to
utilize the nutrients before returning to the fish tank."

you would achieve a result by making the outlet pipes horizontal and joined at a T and ball valve as per my edit in post above.

it looks like that design tends to suck water (and solids) out of the grow bed.

The bold bit is where they see an issue pretty much as Charlie pointed out.

p.s. thanks for an interesting distraction. Interesting to see another variant system to twist the mind around. Some interesting features of that design. I have had to use a small header tank before for my dutch buckets and some adaptation of this flush tank style may have worked then.

But as a starter system it is certainly not KISS. Lot of unnecessary PVC and additional head.

Yup!... Fast F&D cycles are fine, as long as the GB doesn't drain completely with each cycle. I've had a barrel system running for the last six years with F&D cycle times under 5 minutes. Just ensure the siphon cuts off when there is still around 40-50mm of water in the GB, so you're not constantly draining crap back into your FT and it has somewhere to settle out.

Bell siphons are fine for small barrel systems, as long as they are well designed and you size the standpipe diameter accordingly. I use 15mm for barrel systems. Loop siphons are also fine, I've never run them, but I have a number of customers that do. From their feedback the only real issue is with bio-film building up inside the tube over time.

I would avoid timers like the plague. They can and do fail, and Murphy's law will have them fail either when you are away for few a days, or on the hottest day of the year, giving you fish soup in no time at all in a small barrel system. The only way a bell or loop siphon will stop working is if:

(a): The pump stops... Which would be an issue in any system.

(b): The water flow rate alters.

If the flow rate is going to change it usually only ever decreases, normally due to either a low water level in the FT/ST leading to decreased water head assisting the pump, a pump becoming blocked, or wearing out with age. In all these cases the decreased water flow will simply lead to the siphon not initiating, leaving you with a working Constant Flood system until the issue with low water flow is resolved, so no biggy.

As far as the flush tank is concerned, I agree... It's not needed, it just complicates things and is extra expense.

valid points in the siphon vs not to siphon decision process Mr D
*except*
in this case siphons would probably mean rebuilding the system or at least the grow beds.
they could timer F&D or even constant flood *or* simply improve the current setup with minimal modification.

An external syphon could be used with minimal GB interference although Id probably opt for CF

Thanks for the great feedback. I have made some adjustments to my system and the timing is now pretty good. I do have some of my first plantings growing, but I am not seeing a change in any of my nutrient levels. PH is running at a constant 8.2, water temp is around 65 degrees, I have 8 medium sized goldfish and 10 small goldfish, there has been no measureable presence of Ammonia after 6 days. Is this common for a new system? I was expecting a spike in Ammnia early. The entire system has roughly 45-50 gallons of water in it. Any comments owuld be greatly appreciated. Thanks.