This is my 1st system and its been fun getting here. Still a lot to learn.
I'm using a 140 gallon feed tub as a FT and 4- 2 x 3 ft mixing trays as GB's. The media is cinder(lava), there's a lot of that here in Hawaii.
I've ganged the 4 GB together with 2" PVC with drains at the bottom. The drains are 2" shower drains. The system completes with an external siphon dumping back into the FT. The system cycles every 15 minutes and hasn't missed a beat for 2 weeks now(knock on wood).
I'm about done with the fishless cycling, just waiting for the nitrites to drop before adding fish.
Criticism and advice are totally welcome.
I'm trying to post pictures as well. Hope they show up.
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Hi Harold
The siphon I'm using now cycles in 14 minutes. I took the larger one off thinking that a 7-8 minute cycle was too fast. Am I mistaken? Easy enough to change.
Harold Sukhbir said:
Hi Larry,
I noticed the lower drain from your pics. I think the reason why constant flow shows faster growth than timed/F&D is because nutrient water and oxygen contact roots more so than in the case of F&D and ammonia conversion is also enhanced. I also believe the faster the cycling period in F&D the better. If the siphon can manage a faster fill/drain cycle then there could be real advantage this way. May be with the shorter bed height your cycles are as fast as other 12" beds?
I think he means the bottom of the external siphon is below the bottom of the grow beds and the top is situated so that the grow beds flood to the appropriate level. This way the siphon doesn't cut out until after the grow beds are drained all the way down. Basically like saying the grow beds might only be 8" deep but the siphon is more like a siphon for 12 inch deep beds and the bottom 4 inches of the grow beds are virtual
Hi Larry,
There has been much discussion here on optimal draining times. I used to run at 15 min cycles but have since adopted 6-7 min cycles. For me growth is better this way. However there are several contributing factors, sunlight, gravel size, quality of fish feed to name a few. Its easy to check, as my friend Dano suggest, just pull the plant and observe the root structure. More on this discussion here
http://aquaponicscommunity.com/forum/topics/draining-time
Larry said:
Hi Harold
The siphon I'm using now cycles in 14 minutes. I took the larger one off thinking that a 7-8 minute cycle was too fast. Am I mistaken? Easy enough to change.
Harold Sukhbir said:Hi Larry,
I noticed the lower drain from your pics. I think the reason why constant flow shows faster growth than timed/F&D is because nutrient water and oxygen contact roots more so than in the case of F&D and ammonia conversion is also enhanced. I also believe the faster the cycling period in F&D the better. If the siphon can manage a faster fill/drain cycle then there could be real advantage this way. May be with the shorter bed height your cycles are as fast as other 12" beds?
I'm thinking of copying this system for my first system, as it is simple, inexpensive, and would fit in my condo Florida room very nicely.
A few questions for anyone who cares to jump in.
Does it seem like it might be too awkward or difficult to get into the FT to perform regular maintenance? It would be out of the question to move either the tank or GB to access the FT, and I don't know how much access one needs.
Does the GB area seem proportionate to the FT volume?
TCLynx said:
I just tried this external approach, but can't for the life of me get it to work. I should have just stuck with my functioning loop siphon instead of trying to improve things!
In my setup I have 1" drain lines from the beds feeding into the 2" T of the external siphon, which empties through a 3/4" pipe. I've gone through a zillion variations and configurations, affnan mods, etc, but the darn thing refuses to start and when I start it manually it refuses to break.
This week-long ordeal has left me wondering whether siphons really work! What at first appears to be a simple science of simple technology turns out to be a complex art that might take a lifetime to master!!
I think I might have to start over from scratch with my plumbing....maybe a clean slate will help.
Hi Averan
I think your drains are too small for this siphon. I use 2" drains and the siphon I'm using is 1 1/2" outer pipe and 3/4" inner pipe. I have never tested it on drains smaller than 1 1/2". The 2+1" siphon works for me but it drains too fast. I'll try a 1" drain setup today if I get time. Look for an update later.
Hi Averan,
Refusing to start can mean too low flow rate not allowing the water flowing downward to create enough suction to force enough water through the top of the bell. Not breaking could mean insufficient air enters the top of the bell. I built my first bell with an old water bottle, a tube which i got from an old toy. This design is simple, accepts a very wide range of flow rates and has never been serviced for 1 year now.
http://www.youtube.com/watch?v=WzZzjK7aFrA&feature=player_detai...yeah, i saw your video previously. nice design that seems like it solves the breaking issue effectively.
i can't actually do a standard bell siphon as my bed does not have a flat or level bottom.
i have a lot of inflow to play with and certainly more than enough to start a siphon. i'm starting to suspect that these vertical bell-type siphons require more vertical drop on the outflow than loop siphons. my theory is that the loop maintains flow rates so well that there's enough force to create a good vacuum, whereas all the right turns and pressure changes in these vertical siphons slows the water down so much that you need to restore force by increasing the inflow or outflow rates.
the original motivation for attempting this 'upgrade' was to try to create a siphon that would function under a broader range of inflows so that as gunk builds up inside the plumbing from the pump and reduces inflow to the bed, the siphon would still work. so far, my foray into bell siphons has shown me that they are even more picky and difficult than loops! it is probably far easier to design a system to use a bell siphon than to adapt an existing system to use one.
i wish i could step away and take a break from it to get some perspective, but it is way too sunny and hot to let that bed go all day without cycling!
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