Minimal Tank Size

[anthony tran]

Hi all,

I am new with aquaponics.  I would like get your feedback/comments on my AP system.  My goal is to grow edible plants (lettuce and herbs) and fish (cat fish).

The first phase of the system does not have grow bed.  The system has a fish tank with floating raft on top, a filter system, and a sump tank.  The whole thing is all above ground.  I want to keep it simple as I learn.  I think this works because I created an artificial pond.

On the second phase, I will add vertical growing along the West side of the house where I get hit by the afternoon sun.  This provides more vegetables and shade to the house.  I will pump the water from the sump tank to feed those columns and the water will return back to the sump tank.  There is no change to existing system created on phase 1.

On the third final phase, I will add a grow bed as I am limited on the type of vegetables I can grow from phase 1 and 2.  This phase will give me more diversity on the type of plants.  I will insert this GB between the vertical and the sump tanks.

Now I need a place to start this process.  I am running into real estate issue. On the west side of the house, I have 2 feet to put my fish tank.  Is 2 feet too narrow to raise cat fish?  What is the minimal distance?

My second concern is the summer heat.  What is the minimum depth of the fish tank?  I don't want to steam my fish.  They need to find some cold water at the bottom.  I am looking at using EPDM for bed liner.  It is a rubber material and the heat can quickly increase.

Thanks in advance for your advices/opinions/comments.  By the way, I live in Orangevale to give you an idea of the climate.

Anthony

[Butch Pornebo]

following...interested in knowing the answers to the questions too for I am a noob.

would like to add couple of questions of you don't mind.

1) which is better morning sun or afternoon sun. because the available spots I can choose from can only get either.

2) minimum depth of grow bed

regards...

[Butch Pornebo]

at what temp does the catfish thrives on ?

[Tom Hack]

Well I am in Roseville and have a system that is now in its 3rd year of evolution.  Your plan is not necessarily bad but there are some things that you will want to be careful of.

Phase 1 - can work but your filter system needs to have surface area to support the nitrification process this is why most people just start with a Media bed because for small systems it is the Biological Filter serving to remove solids and to provide surface area for the nitrification process.  Will your fish eat the roots - I think that catfish will. Not sure why you need a sump it does not add much value - pump from FT to filter and return to FT or gravity flow from FT to filter and pump from Filter. 

Phase 2 - I see a water temperature problem as vertical towers can really absorb heat against a west facing wall and that will be transferred directly to your water.   I do not use NFT processes as they tend to really impact water temperature plus the more water in your system the more stable it is. 

Third Phase is fine but will not change temperature issue caused by second phase.

Here is a picture of my system.  The fish tank is 2' wide by 2' deep total length is 8' it works fine.  I have 2 half barrel flood and drain media beds over the top of it to provide shade and to protect the fish from predators.  I have a DWC barrel and then my large media bed is a constant flood ( water only height only changes about an inch or 2 due to the flood and drain media beds.  

I used Durascrim liner it is white and I got 6' width by 50' long for about $150 and I have some left over to add more to my setup.

As far as the other questions put your system where it will get the most hours of Sun.  I don't believe that the time of day really matters as much as the total time in the sun.  My system gets some morning sun and then gets some shade from the neighbors tree in the afternoon and it is doing fine.  

I have 3/4" insulation between my liner and the cinder blocks which really helps my water stay a constant temp. 

Tom

[anthony tran]

Hi Tom,

Thank you for your inputs.

fish eating roots...you have the point here.  I need to consider breaking it as a fish tank and raft tank.

sump tank... this is for future expansion into grow bed.  I have it set up early for less pain adding more beds down the road.  I agree that phase 1 does not need it.

Agree on temperature problem... I have to have more water in the system for stability, reduce the number of vertical, add insulation where appropriate.  Can I have vines plant on my vertical?  I can use that for shade.

Your system is 2 feet wide.  what kind of fish do you have?  does it impair growth?

Durascrim liner...can I staple it to my wood frame?

Media with constant flood...so you do not use siphon bell.  what is the advantage of using either one?

Thanks,

Anthony

[Jon Parr]

Catfish are ok in rafts, or at least I have had no issues with them, and have had them in rafts for 5 years now. The issue is from the barbs on the catfish when they get big, punching holes in the skrim. Yes you can staple DuraSkrim to the rails, and I usually cap that with a board to protect it all from UV.

Yes, vines are much better use of vertical space than other plants grown in a some form of vertical support and plumbing, IMO. 

And insulation works both ways. It slows the transfer of heat, both gain and loss. This is good if you are trying to keep water warm in a cold environment, but bad if you are trying to use the thermal mass of the earth to keep out summer heat. In my greenhouse, nothing is insulated, and I maximize hearth contact with liner and tanks. Min temp was 54 last winter, and max was 78 in the summer. 

Everybody has their own style, but I don't use flood and drain, or bell siphons, or timers. I use DWC and wicking beds. 

Catfish grow fast in the high 70's, low 80's. They can survive down to freezing, but will not eat much or grow below 60.