ebb and flow vs constant flow

[glenn wilkerson]

simple question almost which one is better

[matt]

Most plants will do well in Ebb and flow. Some plants like lettuce do better in DWC. What exactly do you mean by constant flow? NFT, DWC, or something else?

[Debra Colvin]

I've heard ebb and flow recommended more than continuous flow. Both of mine are continous flow during daylight hours, and some of the beds never drain completely. i really don't know which is better since my systems have always been based on continuous flow for simplicity's sake. I am also far from a great success, but I do highly enjoy what has grown this way in the past.

[Mike Walsh]

I asked the same question when researching my first set-up.  I opted for using Affinan's mini-siphon.  It has been very reliable so far and easy to construct.  Give it a whirl!

[Sylvia Bernstein]

In the latest version of Backyard Aquaponics Magazine Joel describes a comparison he did between constant flow, timer, and bell siphon based grow beds.  The test had only one grow bed for each so as he points out it wasn't really scientific, but definitely interesting.  The results basically are that there is not a lot of difference between them (click here to download an issue of the magazine if you would like more details).  Murray Hallam has run similar trials with similar results.  Even if you don't see a lot of difference in growth, personally I would always do an ebb and flow style system in media beds because you pull so  much oxygen  into the root zone when the bed drains, which is good for the health of your plants - both long term and short term - and for your worms!

[litano]

what about bell siphon vs loop siphon? and what is the cheapest and best growing medium?

[matt]

The normally 3/4" or 20mm no fines gravel is the best growing medium for the cheapest. You can go smaller or larger, but 3/4" is what is recommended. Depending on how you get your parts a loop siphon should be much cheaper to construct.

[litano]

where can I get the gravel,, is it regular Pea Gravel from HD? thanks,

matt said:

The normally 3/4" or 20mm no fines gravel is the best growing medium for the cheapest. You can go smaller or larger, but 3/4" is what is recommended. Depending on how you get your parts a loop siphon should be much cheaper to construct.

[matt]

no its larger then pea gravel 2-4 times the size. You can pick it up at a quarry or gravel supplier. Some landscapers keep it in stock as well.

[TCLynx]

There is a difference between constant flow but flood and drain via siphon and constant flow constant flood systems and yet more difference to a system that is constant flow but not flood (this might be a trickle through set up and doesn't get as much filtration as any of the other media based systems.)

 

Constant flow/flood seems to be fairly effective for bio-filtration and just fine for many plants while timed flood and drain seems better for some plants that prefer a more dry situation while siphon flood and drain with constant flow is also a good option.

 

Which type of siphon is better will depend on the situation and materials at hand.

 

What type of media, well there are many great types of media.  A bit larger than pea gravel is generally best.  I've been using 1/2" brown river rock which is the cheapest pH appropriate choice around here.  Be careful with "pea gravel" since that only describes the size/shape and the type of rock is more important.  If I were to order the cheapest pea gravel I can get around here, it will be limestone and that will keep the pH too high.  If you can get 3/4" gravel that will be a good choice too though 1/2" does work.

 

 

 

[Allisyn Wood]

As of right now, I don't have a timer on my pump.  I use a bell siphon in each of my river rock beds (3 total) that continuously flood and drain about once every 10-15 minutes.  I am noticing that some of my plants don't like this, but it could also be user error.  In your experience, which plants like the constant f&d and which do better on a timer, say 15 on, 45 off?  So far, the squash, melons and some of the herbs look mooshy.  Strawberries could look better, too.  Hoping to get hooked into an indexer soon if I can beef up the pressure, but until then...

TCLynx said:

There is a difference between constant flow but flood and drain via siphon and constant flow constant flood systems and yet more difference to a system that is constant flow but not flood (this might be a trickle through set up and doesn't get as much filtration as any of the other media based systems.)

 

Constant flow/flood seems to be fairly effective for bio-filtration and just fine for many plants while timed flood and drain seems better for some plants that prefer a more dry situation while siphon flood and drain with constant flow is also a good option.

 

Which type of siphon is better will depend on the situation and materials at hand.

 

What type of media, well there are many great types of media.  A bit larger than pea gravel is generally best.  I've been using 1/2" brown river rock which is the cheapest pH appropriate choice around here.  Be careful with "pea gravel" since that only describes the size/shape and the type of rock is more important.  If I were to order the cheapest pea gravel I can get around here, it will be limestone and that will keep the pH too high.  If you can get 3/4" gravel that will be a good choice too though 1/2" does work.

 

 

 

[Nate Storey]

Ebb and flow is generally better for your plants, like TC and Sylvia said.  I'm not sure what you mean by "mooshy", but if they're experiencing soft rot, root rot, or a crown rot of some kind, they're probably getting too much water and possibly experiencing some anaerobic conditions.  I'd try a longer flood and drain cycle- esp. if your media is holding lots of water or has a lot of muck or organic matter in it.

[Allisyn Wood]

Hum... My system is only a couple of months old so the muck shouldn't be a problem... it takes about 15 minutes for the beds to fill and only about a minute or two to drain, so it should be getting some oxygen sucked down into the roots.   I can't really change the timing on the cycle as the flow is perfect to kick the siphon.  Anything less wouldn't work.  Been trying that... I'd rather put the thing on an indexer, but still trying to figure out that one.