DWV Question

[L F]

I understand the difference between NFT & DWC but my question is how deep is the water in each system?      I want to build one or the other after  the growbeds  but I want if to be gravity flow so I need an elevation shift between it and the GB.  Also which would be better? I dont plan on using except to only grow lettuce when weather permits. Thanks in advance.L F

[L F]

TC there are enough kids around here to get the fish out. I should be able to see the tank easy enough as I'm not making my GBs but only  4ft wide and the FT will be longer than the GBs. The reason for the FT in the green house is to help control the temp. in the winter. It dont get really cold here but we get maybe a week below freezing. I have an eletricit heater to knock off the chill but it will break the bank to run it very much.

[TCLynx]

Just making sure you think about accessibility as I've cursed myself when I didn't make things easy.  Perhaps a mini seine sort of net that you could place into the tank on one end and pull to the other end using ropes or chains until the fish were all grouped into an easy to access area for harvest.

[L F]

TC and Harold and any others I always get good answers here but given time I seem to come up with more questions. It seems that more people are edging towards a GB,DWC and NFT combonation. After much thought Ive come up with a way to do this and if it dont work I can convert my DWCs to GBs by adding gravel. Between ranching and my regular job things are going slower than I hoped But I hope to get construction started in about 2 weeks.My question is will 32sq ft of GB feeding 64sq ft of DWC which feeds about 10NFTs each being 13ft long 4in pipes.? I can easily convert half of the DWC to GB but then it will be suppling the NFTdirectly. I sure hope everybody can understand this question.  Thanks again for all the great information.  L F

[TCLynx]

The only question mark I see doesn't actually have a question in the statement.

Are you asking if a grow bed could feed a NFT directly, well sure if the heights all work for it or if you will have a pump to take care of it.  I would avoid having a flood and drain media bed feed NFT pipes directly since the gush of water out of a siphon or as the beds overflow would be hard on the plants and you want NFT to have a constant small flow of water.  So you would probably need a sump tank of sorts to do it easily, unless the grow beds are constant flood.

[L F]

Thanks TC I can build a sump between the GBs and the DWC [ I hope this is what you were saying ] and then let the water trickel in and out of the DWC to the NFT. Now will 32sq ft of GB support 64sq ft of DWC and some NFTs? By the way they gave mem a diploma so I wouldnt come back to school.   Thanks again,you're very helpful and informative. 

TCLynx said:

The only question mark I see doesn't actually have a question in the statement.

Are you asking if a grow bed could feed a NFT directly, well sure if the heights all work for it or if you will have a pump to take care of it.  I would avoid having a flood and drain media bed feed NFT pipes directly since the gush of water out of a siphon or as the beds overflow would be hard on the plants and you want NFT to have a constant small flow of water.  So you would probably need a sump tank of sorts to do it easily, unless the grow beds are constant flood.

[TCLynx]

Actually I was thinking more along the lines of a SUMP after the DWC (since you mentioned possibly converting the DWC to a media bed in needed.)  And NFT is usually up higher than a raft bed since raft beds are usually on the ground and NFT is more commonly set up at waist high so you would need a pump to lift water up to the NFT portion of a system.

 

Now the big dollar question?  Is x amount of growbed enough to supprt Y amount of raft bed?  That depends and we are still working on figuring out the answers.

Not many mixed method systems have been in operation for very long so the long term answer is not very certain yet.

The short term answer will be, Depends on how many fish you have, how much you feed them and what sort of plants you are growing in the different parts of the system. 

-I can tell you that if you live in Central Florida and have like 100 bluegill eating well in the fish tank and plant two lufa vines in your 32 square feet of grow bed and it's summer and the lufa vines grow up over the top of the 30+ foot oak tree near the system, there won't be much nutrients left for your raft bed.--  But then come fall when you rip down those lufa there will suddenly be plenty of nutrients for the grow beds and raft and NFT until it gets so cold that the fish stop eating.

 

Most importantly, you want to make sure that the grow bed is enough filtration for the amount of fish you are going to stock and then once the system is well cycled up you will get to see if you have excess nutrients for your plants and need to add more or is there not enough nutrients and you either plant less or see if your filtration and dissolved oxygen will support more fish.

 

Aquaponics is all about balance and each system and situation will have a slightly different balance point and you have to learn that for yourself.

[L F]

Thanks again TC  I was planning on only using the NFTs in the winter for lettuce and such and very little or none would be in the GBs at this time. I would then plant in the GBS and basically drop the NFTs in the summer. I understand what you mean about balance but the closer you start in the middle the easer it is. Thanks so much for the information  LF

TCLynx said:

Actually I was thinking more along the lines of a SUMP after the DWC (since you mentioned possibly converting the DWC to a media bed in needed.)  And NFT is usually up higher than a raft bed since raft beds are usually on the ground and NFT is more commonly set up at waist high so you would need a pump to lift water up to the NFT portion of a system.

 

Now the big dollar question?  Is x amount of growbed enough to supprt Y amount of raft bed?  That depends and we are still working on figuring out the answers.

Not many mixed method systems have been in operation for very long so the long term answer is not very certain yet.

The short term answer will be, Depends on how many fish you have, how much you feed them and what sort of plants you are growing in the different parts of the system. 

-I can tell you that if you live in Central Florida and have like 100 bluegill eating well in the fish tank and plant two lufa vines in your 32 square feet of grow bed and it's summer and the lufa vines grow up over the top of the 30+ foot oak tree near the system, there won't be much nutrients left for your raft bed.--  But then come fall when you rip down those lufa there will suddenly be plenty of nutrients for the grow beds and raft and NFT until it gets so cold that the fish stop eating.

 

Most importantly, you want to make sure that the grow bed is enough filtration for the amount of fish you are going to stock and then once the system is well cycled up you will get to see if you have excess nutrients for your plants and need to add more or is there not enough nutrients and you either plant less or see if your filtration and dissolved oxygen will support more fish.

 

Aquaponics is all about balance and each system and situation will have a slightly different balance point and you have to learn that for yourself.

[TCLynx]

Chris Smith might be a good one to ask about how much grow bed per some amount of fish and some amount of Raft bed since he has been running a mixed grow bed/raft system for a while though he is doing it in Hawaii so climate may be different than what you will be dealing with.

[L F]

Ok I can put the sump after the DWC , no problem if it ain't built yet. As for the water flow my GBs will be on the hill I will build while digging my FT. Got to put that dirt somewhere just as well use it. I figure this will give me 3 growing levels with a total drop of 3ft. Thanks again for the help. 

TCLynx said:

Actually I was thinking more along the lines of a SUMP after the DWC (since you mentioned possibly converting the DWC to a media bed in needed.)  And NFT is usually up higher than a raft bed since raft beds are usually on the ground and NFT is more commonly set up at waist high so you would need a pump to lift water up to the NFT portion of a system.

 

Now the big dollar question?  Is x amount of growbed enough to supprt Y amount of raft bed?  That depends and we are still working on figuring out the answers.

Not many mixed method systems have been in operation for very long so the long term answer is not very certain yet.

The short term answer will be, Depends on how many fish you have, how much you feed them and what sort of plants you are growing in the different parts of the system. 

-I can tell you that if you live in Central Florida and have like 100 bluegill eating well in the fish tank and plant two lufa vines in your 32 square feet of grow bed and it's summer and the lufa vines grow up over the top of the 30+ foot oak tree near the system, there won't be much nutrients left for your raft bed.--  But then come fall when you rip down those lufa there will suddenly be plenty of nutrients for the grow beds and raft and NFT until it gets so cold that the fish stop eating.

 

Most importantly, you want to make sure that the grow bed is enough filtration for the amount of fish you are going to stock and then once the system is well cycled up you will get to see if you have excess nutrients for your plants and need to add more or is there not enough nutrients and you either plant less or see if your filtration and dissolved oxygen will support more fish.

 

Aquaponics is all about balance and each system and situation will have a slightly different balance point and you have to learn that for yourself.