understanding the economics

[Lance Rose]

I am trying to keep books on my setup so that I can gauge how to expand without robbing a bank.

I hope to kickoff a discussion about relative cost and economies of scale. 

For my current setup, I have "free-sourced" just about everything but the fish and plants. But now I am running into some stuff I did not account for, which will cost me a little. For example, the testing kits.

I have water in 2 55 gallon barrels. So I guess I have about 100 gallons of water. I have 50 coppernose bluegills. The growbed is 1 55 gallon blue barrel split in half.

My startup cost were about $50. $25 for plants and $25 for fish. I also had a little plumbing couplings to buy.

If I had paid retail for all the stuff,

Barrels (?) I am seeing $30 each on a couple of websites = ($90).

Frame wood ($30)

PVC (10' 1", 10' 3/4") plus couplings, glue ($30)

Rocks (this one is hard) If you buy bags at Loews/HD (15 X $3 = ~$45), Or $1 per bucket at a local aggregate seller (~$15). 

Pump, ($45 at Loews/HD)

Around $200. Sound right?

So startup will cost between $0 (catch the fish from pond and get plants from other source) to $250

In a 3'X2' grow bed, I think I can get some strawberries, Okra and a couple of tomatoes. I might get $20 worth of produce.  If I manage to kill 0 fish, I will get 50 good sized bluegills which have a value of (what?) If I buy fish at walmart, it is $4-$5 for a package of 2. So for eazy math, I will say $2 per fish = $100.

So my output value is in a range of $0 (all die) to $150 if everything goes right.

My ongoing cost are food, electricity, water and testing.

Food so far is a bag of commercial feed, I got that for $15. I expect to use a lot more in the future, but right now, not so much. 

Electricity is ?. I have no way of measuring the actual usage. I'm not sure how to convert watts or amps to actual unit of energy I get charged for.

Water. I have a well, so my water use is basically electricity. Plus I am adding a little water every other day. This will be more in the summer. But again, I dont know how much this cost me.

Testing (~$15/kit). I am testing once week for 1 week so far. I'm not sure how long this kit last. I'm guessing 2 months.

So if a bag of food and a test kit cost me ~$20/month.

Am I missing anything? I am trying to make an Excel spreadsheet to cover my cost as I go.

[Lance Rose]

No problem. I love the idea of comparing numbers. My profit, if any, will be money saved from buying veggies and strawberries. But I do eat a lot of strawberries!

Chris said:

Sorry I didn't mean to say you shouldn't budget or estimate costs at all. I misinterpreted what you said as you planned to reinvest profit to expand the system and of course you should but I don't think planning on it will work out as well as hoped. I don't think I have ever done any DIY experiment that came in on budget, even a pessimistic one planning for rebuilding and gas for a billion trips to the hardware store

Regarding your electricity usage, your bill should say how much a kwh is (killawatt x hour). That is how much it costs to run 1000watts for 1 hour. If you know the wattage of your pump(s)/lights you should be able to estimate costs based on how long they are on per day.

If you don't know the wattage of a pump, I believe by law it has to have input voltage and amp usage on it. wattage = volts x amps

Lance Rose said:

I'm not looking to use the numbers to "turn a profit". 

[Lance Rose]

I moved about 35 of the fish to my cattle pond. 

I did not have the API master kit. I will get that when I go to work tomorrow. I have a Mardel 5 in 1. I do have an API PH test kit.

My numbers from this morning.

O3 - 40ppm

O2 - .5 ppm

Hardness? - 0

Alkalinity - 120

Mardel PH 6.0

API PH 6.4

[TCLynx]

Might want to do something to buffer the water up a bit before the pH falls too much more.

I'm a bit worried about the ammonia level so I would say DON'T FEED until after you can check that and make sure you are not experiencing a terrible ammonia spike already.

[Lance Rose]

"Buffer the water up"? Suggestion?

I did not feed them today. I was planning on not feeding them tomorrow.

Thanks.

TCLynx said:

Might want to do something to buffer the water up a bit before the pH falls too much more.

I'm a bit worried about the ammonia level so I would say DON'T FEED until after you can check that and make sure you are not experiencing a terrible ammonia spike already.

[Cliff Jagger]

I own Asheville Aquaponics in Asheville, NC.  I run 1500 gal. and 100 feet of planted tubes.  My electric cost is apprx. $35/mo. I run 2 solar fans and 2 electric fans for my micro greens & a 14 valve air pump.

The biggest mistake most people make is they over think their systems.  I catch my water in a rainbarrel.  I have seen people with the same size system as mine and their electric bill is over the top !

You dont need subpumps & bell syphons and a major water pump.

Their is a picture of my greenhouse at:  http://www.AshevilleAquaponics.com

 

[Chris Carr]

I agree with making gravity your friend. I am in Charlotte so ill have to stop up sometime to check out your greenhouse(s). Looks great!

Cliff Jagger said:

I own Asheville Aquaponics in Asheville, NC.  I run 1500 gal. and 100 feet of planted tubes.  My electric cost is apprx. $35/mo. I run 2 solar fans and 2 electric fans for my micro greens & a 14 valve air pump.

The biggest mistake most people make is they over think their systems.  I catch my water in a rainbarrel.  I have seen people with the same size system as mine and their electric bill is over the top !

You dont need subpumps & bell syphons and a major water pump.

Their is a picture of my greenhouse at:  http://www.AshevilleAquaponics.com

 

[TCLynx]

Buffering the water up

Refers to adding a carbonate buffer to the water that will keep the pH from dropping too low or buffer the pH up.

Common buffers include calcium carbonate (lime or shells or chicken grit) or potassium bicarbonate (find it at brew and wine making supply places)  The calcium carbonate provides calcium while providing the needed alkalinity to the bacteria and potassium bicarbonate does the same while providing potassium instead of calcium.

There are also pH up methods that are far more alkaline and fast acting and must be treated with caution but it is what the big boys use at the University of the Virgin Islands.  That would be Calcium Hydroxide (hydrated lime) and Potassium Hydroxide (old fashion Lye).  These are both caustic substances and must be handled with care and proper protective equipment but they still work to keep pH up and provide calcium and potassium.

[Lance Rose]

Ok. It rained all day so I didn't get to test my water. I will in the AM.

[Cliff Jagger]

If you want to raise your PH just add Baking Soda.  Only add one teaspoon per 200 gal every other day til it is where you want it to be.  If you want to lower your PH just add White Distilled Vinegar.  Only add 1/2 cup per 200 gal every other day til its where you want it to be.  These two methods will adjust your PH immediately.  You dont need to go to the local aquarium store to buy some expensive stuff that you already have in your house. (:

This is what we use at http://www.AshevilleAquaponics.com

[Vlad Jovanovic]

IMO it might be best to avoid baking soda unless it was a one time thing done in a pinch situation...You can buy a pound of Potassium Bicarbonate for under 10 bucks (or enough Potassium Hydroxide to last you a decade for the same amount of cash). 

And doesn't vinegar have a pretty looong history of being used as an anti-bacterial agent? Might not be the best thing to use when rearing bacteria in a bio-filter. (14-16% solution of HCL is 80 cents a litre where I'm at. It takes literally like half a teaspoon to the gallon)...

[Lance Rose]

I measured this morning and it is at PH of 6.5 (Mardel) 6.8 (API). Does that seem like a lot of climb in a few days?

I finally got a full test kit and will start the full testing daily tonight.

I also got a handful of strawberries this morning. And there are a pink bunch that will turn red in the next few days. Base on what I spent, that is about $6 a strawberry! But the cost is coming down every day. 

For a proof of concept hobby tank, I think that is pretty good!

Back to the original idea of the post, What are some representative numbers from some other folks? I drew up a plan for a ~200 gallon (10X3X1 = 30 cu ft * 7.5 = 225 gal) in ground fish tank covered by a ~200 gal grow bed with a heat pump built in to keep the water cool in the summer and warm in the winter. The cost I estimate, using all commercial pricing (I usually free source stuff) would be about $500. I estimate my actual cost to be around $150-$200. Mostly for a couple of pumps. 

How much strawberries can I grow in a 30 cu ft bed? 

What about in six 10' long 3" PVC pipes? How far apart can I put the plants in a PVC tube?

I have included a BMP of my bed idea and a Excel spreadsheet of my estimates for commercial priced. 

Again, Thanks for all the input, it is really interesting and greatly appreciated.

[Lance Rose]

Added the Excel