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Spooky__Fish
02-26-2011, 04:29 PM
I have 4 indoor ponds used to growout ornamental Cichlids. The ponds are 500-1,000 gallons, and I would like to add aquaponic systems to them in order to maintain better water quality and minimize/eliminate water changes. The vegetable crops are a big added bonus, but not the main intent.

My hatchery is designed for simplicity, low labor, reliability and really low cost. I would like to approach aquaponics the same way.

I'm thinking that the 4 separate ponds should all have there own independent aquaponic system. I'm cogitating using barrels cut in half with pea gravel and a bell siphon fed directly by pumps submerged in the ponds and lit with fluorescents.

Is pea gravel my best bang for the buck? I guess a masonry supply place the best source?

I got barrels but they are white/clear, is algae going to be a problem, benefit or non-issue?

Do the center of the barrels need to be supported? If so, what is recommended? It looked like Badflsh was using zip ties?

I found the stainless fluorescent fixtures that Badflash recommended, but they take two 32watt T8 bulbs. That don't seem like enough light to me, but I'm a total newbie and know nothing. Can 1 fixture supply sufficient light for 1 barrel?

The ponds get filled with 3/4" fish which grow out to 2". Obviously the nitrate production changes greatly as they grow. I'm wondering how you calculate how many barrels you would need per pond, and thinking the number changes over time?

I'm looking to do crops that don't grow too tall and grow fast. I'm thinking mostly mesclun salad mix, cilantro etc. My African Cichlids and ancistrus cats get fed zucchini and green beans occasionally. I don't want to grow those two plants, but would like to grow something to feed the fish. Any suggestions? Any veggie they will eat and I can make sink is a big +

Any comments and suggestions are much appreciated!

keith_r
02-26-2011, 05:03 PM
welcome aboard, sounds like a great way to get your feet wet!

i think a separate system for each pond would be the way to go

as far as "pea gravel" - you don't want something "pea" size, maybe a little bigger, like river gravel, and stay away from limestone (you can test your media with vinegar, if it bubbles you don't want it) - landscaping places are a good source as well as home depot type places

white barrels will break down from uv faster than blue/dark, but the dark colored barrels absorb more heat..i use barrels, and am thinking of some kind of "skirt" around them next summer (seams like a long way off, had a foot of snow yesterday) - the barrels need support across the bottoms and sides, google "travis hughey" for a good barrel stand idea

regarding the lights, i've got 3 t8 pairs across 2 growbeds, and have radish, green peppers and salad mix sprouting, other stuff looks ok, i have 2 pair with "cool" lights, 1 with "warm"

if you have a good ratio of growbeds to pond volume (1:1 is good, 2:1 is better, thats growbed to fishtank) you might want to raise the beds up (so they are easy to sow and harvest) and use sumps if you go with a higher volume of growbed so that you don't drain your ponds when cycling water, or look into "sider valves" and fill growbeds in sequence, with the right filtration, you don't really need to do water changes,, aother way to look at growbed volume is 25lbs of "grown out" fish to 100 gallons of filtration/media, that'not a "law" by any means, but a good rule of thumb.

good luck and take lots of pics

badflash
02-26-2011, 05:37 PM
I get my barrels for free from the local car wash. Most of the stuff they use is safe as long as you wash it out well. I split them the long way and use a big zip tie to hold the middle from expanding.

Spooky__Fish
02-28-2011, 09:46 AM
Thanks for the replies.
I got 2 serious issues I am working on now.

1) I raise African Cichlids, which come from hard Alkaline water. My water here is around 8.5, which is great for the fish.
Best I can tell, if I want to grow anything other than algae, I need to lower the PH on the ponds. The fish can probably deal with the conditions, but now I would have different water chemistry between the ponds and the 150 tanks. The fry will have to be acclimated before introduction to the ponds, and the grown-out fish acclimated back to the tanks from the ponds. To adjust PH, should I be thinking about a buffer or just an acid safe for the fish and plants?

2) My biometrics are vastly different from raising food fish. This may make keeping an AP system in balance very challenging.
A) My target density is 4 fish per gallon. At the introduction phase, this translates to 0.002 Lbs/gallon and 0.035 Lbs/gallon at harvest.
B)From when I introduce fry to the ponds, my time to market is only 3-4 months.

I'm thinking, my systems need to be plumbed so I can remove barrels from a harvested pond (soon to be filled with fry) and add them to the other, more advanced ponds.

I'm also thinking, I need a lot less grow bed space than you folks!

badflash
02-28-2011, 08:11 PM
Don't over think it. The stock SS fixtures from walmart are fine as are daylight bulb. Buy some back up ballasts as they go after about a year. Young plants pull out more nitrates than mature ones, so keep harvesting. With a volume as large as yours, just sample for nitrates and adjust when needed. You can add fast growing water plants like najas if thing get out of hand, just light the tank.

Do a little digging, lots of greens do fine with high pH, and lots of cichlids do fine with a lower pH. Don't fight your water. Match your plants to what you have. Najas loves cichlid water, but you can't (or I don't) eat it. I'm sure other plants love high pH water too. I've just never dug in and figured out what.

urbanfarmer
03-01-2011, 08:47 PM
Basically, in an aquaponic system you have 3 groups of living organisms to consider. The fish, the plants, and the bacteria. Since you are going with a gravel grow bed, the invertebrates (such as worms) that help break down solids and sludge are also important, but seem to thrive all on their own.

In my opinion, pH is the single most important "number" in an AP system. As you probably know, unionized ammonia is what really hurts fish and not the TAN (total ammonium nitrogen). To give you an idea from your pH of 8.5 compared to a pH of 5.5, you will have ONE THOUSAND (x1000) times more unionized ammonia in your water than if it was 5.5!!! I am less familiar with specifics in aquaculture. Is there a benefit to the high pH of the water for the fish? If so, that is something to consider.

With that said, I am not suggesting you try to keep it at 5.5, but that a lower pH could greatly benefit the water quality of the fish as well as the plants. In general, a pH of 8 does not adversely affect the harvest potential of some veggies (although for herbs, leafy greens, and early harvest plants it may). Also, a higher pH is better for the bacteria in the system... but as with all aquaponic systems, finding the right balance for your specific environmental conditions is the True answer. As a rule of thumb, we suggest a pH somewhere between 5.5 to 8.0 with 6.5 to 7.0 being generally safer for most people, but the latter range may not provide the optimal performance.

Duckweed is a popular plant to grow and feed to tilapia. The protein content is supposedly ideal for them. Milwaukee's Growing Power uses watercress (I think) and he seems pretty happy with it as a filter for the fish. If I'm not mistaken, his system is optimized for the fish as opposed to the plants or an equal balance for both.

OH, and Home Depot has $10 shop lights (with hanging chains) that take 32 or 40 Watt T8 bulbs. The bulbs are $1 and 4100K color with around 3200 Lumens (if I recall). The metal on the shop light casing is thin enough to drill sheet metal screws through to build a fixture with as many lights as you need. In my experience, they pump out quite enough light. I grew peppers in my indoor system, and I got better results than outside (due to other factors than the light).

urbanfarmer
03-02-2011, 07:51 AM
I just stumbled across this. It could give you some ideas also:

THE FEEDING PREFERENCES OF TILAPIA AUREA FOR FIVE AQUATIC PLANTS
http://digital.library.okstate.edu/oas/oas_pdf/v64/p14_16.pdf

Spooky__Fish
03-02-2011, 09:10 PM
Thanks for all the info.
I wanna stay away from aquatic plants and lighting the ponds.
I think I'm going to setup a single barrel as a test to see what will grow. I already got lettuce seeds started and a barrel ready to be cut!


Is there a benefit to the high pH of the water for the fish?
The water they come from has a PH of 7.7 to 8.6. Besides that fact, I know of no benefit they receive from those conditions, or any reason they won't thrive at a lower PH. However, fighting my water as Jack mentioned, is something I'd really like to avoid.

jcx
03-02-2011, 10:55 PM
This may be helpful.

This chart shows your P.H levels effect on the availability of nutrients.
I don't grow a very wide verity of plants, I would guess there is something that can live in 8ish.

jcx
03-02-2011, 11:45 PM
Also found some links for plants that will grow in alkaline soil. Looks like there is not too much in the veggie department, maybe something will work for ya.

http://www.ehow.com/list_5914782_plants ... oils_.html (http://www.ehow.com/list_5914782_plants-like-alkaline-soils_.html)

http://www.thegardenhelper.com/alkalineplants.html

keith_r
03-03-2011, 06:38 AM
the nitrification process will bring your ph down as your system matures

Spooky__Fish
03-03-2011, 09:44 AM
http://diyaquaponics.com/forum/download/file.php?id=866&t=1
Thanks for posting the chart, that displays what I have been reading.
Iron appears to be the biggest problem with high PH. My water is very high in iron and calcium, but despite the amount of iron, the chemistry may make it mostly unavailable to the plants.

Regardless of the facts, I'm going to experiment to see how practical results compare to theory. There are many successful things I do in aquaculture that are diametrically opposed to theory. I'm not afraid to attempt something that bucks convention. I figure if iron is a problem, chlorosis will be the response, and it will be very easy to diagnose. I also figure wrong a lot :roll:

I'm wondering if the calcium may be an issue? As it is, calcium precipitates out of the water and coats the ponds, tanks and filters. I'm thinking that if I drop the ph, the roots may turn into stalagmites?


the nitrification process will bring your ph down as your system matures
It would need to change it profoundly, I doubt that process would do more than drift the PH down slightly over time.
Regardless, I much rather use the high ph water I have, if I can.

badflash
03-03-2011, 08:54 PM
Again, don't fight the water. The water will win. Find plants that like what you have to offer. Iron is easy. Add a little blood meal. Remember, you want to grow greans and reduce or eliminate water changes. If nothing else, toss the plants on the compost pile. You'll probably end up eating them. My peacocks eat the aquatic plants, so I need to separate them.

urbanfarmer
03-04-2011, 06:29 PM
It would need to change it profoundly, I doubt that process would do more than drift the PH down slightly over time.
The pH "drifts" faster at higher pH than at lower pH. The pH "drifts" 1000x times faster at pH 9 than at ph 6.

2 NH3 (ammonia) + 3 O2 (elemental oxygen) ==> 2 NO2 (nitrite) + 2 H (hydrogen ions) + 2 H2O

In other words, for every mole of ammonia it will yield a mole of hydrogen ions. Therefore, 1 mole of ammonia in 1,000,000 Liters of water later and your pH will go from 7 to 6 (roughly). Translated, that means that for every 142 grams of food (assuming 30% of the protein in the feed converts to ammonia for 40% protein feed) per Liter will lower your pH 1 point from 7 to 6. 142 grams is not a lot of food in itself; so, multiply that by how many liters (multiply your gallons by 3.78) are in your system and that will give you how many grams of food until your pH drops by 1. This ASSUMES your fish EAT all the food. Food that does not get eaten will produce far more ammonia.

It's 12 pounds of food per 10 gallons of water (assuming you have the fish to process the feed). It does not matter if you feed the 12 pounds of food over 1 year or 1 month. The pH will drop to 6 after 12 pounds of feed converts to ammonia and then nitrite.

Interestingly, if your pH was 9 the same amount of feed would roughly change the pH to 6. I know, that might not make sense, but remember pH is a measure of the negative algorithm of the hydrogen ion concentration. My calculations above are for adding 1 mole per 1,000,000 liters; therefore the new pH is the sum of the previous hydrogen ion concentrations, which if coming from a HIGHER pH will always yield a little tiny bit less than a pH of 6.

This also means that if your pH is 8 or higher it will only take 1.2 pounds of feed per 10 gallons of water to lower your pH to 7. Now that's not a lot of feed at all!!!

At a general stocking density of 1 pound of fish per 5 gallons of water with a grow out of 6 months and a 1:1 ratio of food to grow to the stocking density, it would take about a year to go from a pH of 8 to 7. That simplifies the situation to having the fish NEVER grow. As we know, fish grow and require different feed at different stages of growth.

I'm not sure if I messed something up here, I just ran through all that as a personal exercise while listening to some very loud children... but, assuming I wasn't too far off, that should give you SOME idea because the pH is not linear whatsoever.

THE MORAL OF THE STORY: DON'T BOTHER CHANGING YOUR WATER. :lol:

MWAHAHAHAHAHAHAHAHAHA :ugeek:

Spooky__Fish
03-04-2011, 07:19 PM
THE MORAL OF THE STORY: DON'T BOTHER CHANGING YOUR WATER.
I like the idea, but even if that's correct it still don't work for me. Remember, my metrics are much different from tilapia, I'm starting with tiny fish and growing to 2".
At my target density of 4 fish per gallon, were probably talking an average of .125Lbs./day for a 1,000gal pond. That's 0.00125Lbs./day/10gal or 0.456Lbs./year/10gal or 4.5Lbs./decade/10gal or 27 years till the 12 pound number is reached :shock:

Regardless, thank you for taking the time to compose such a cogent post. I'm so used to the inane droning on other sites, that I found your use of facts, mathematics and logic especially refreshing.

badflash
03-05-2011, 11:47 AM
4 fish per gallon of that size is a pretty light bioload. I'm at around 1/4 pound per gallon in my system. I'm running peacocks as well as tilapia.

keith_r
03-05-2011, 12:38 PM
my system was pretty steady at a ph of 7.6 to 7.8 at least into november, from late april or early may (the last time i tested the water was 11/6)
today the ph is at 6.4, maybe a little less
i've only been lightly feeding the new fish and the bigger ones have been eating lightly as well, amonia was at less than .25, nitrites were a little high at .5 and nitrates were at 40.. as an aside, i'm pretty happy with how 3 pairs of t8 lights are doing

Spooky__Fish
03-05-2011, 12:59 PM
4 fish per gallon of that size is a pretty light bioload.
Yes it is.
Current load is 1.2 fish/gallon due to the limit of my current production. My goal is 2 fish/gallon, however with AP I'm thinking I can easily double that to 4 fish/gal and have better water quality. 4 fish/gallon would be a big win and make me very happy, once again...my metrics are very different from tilapia.

Spooky__Fish
04-29-2011, 12:55 PM
Well my experiment failed.

I did a floating raft with mesclun mix.
All red leaf and light green varieties could not grow successfully.
Darker green leaf ones technically survived but did not produce anything that could be considered a crop. Clearly the nitrate consumption of barely living specimens is negligible.

I'm glad I did such a small scale test instead of investing in something production size. Looks like I can't do AP without changing the Ph of my water, and that ain't happening.

Thanks for all your help. Now I know you can't do AP with lettuce at Ph 8.5!

urbanfarmer
04-29-2011, 09:31 PM
WOW Spooky__Fish, I AM SO SORRY NO ONE RESPONDED TO YOU SOONER.

I am 100% confident aquaponics can help you achieve what you are trying to achieve. There is NO reason why it wouldn't work if your only obstacle is a slightly high pH. Your pH is perfectly workable... One note on "fighting the ph" have you tried something cheap like hydrochloric acid? It's available at most pool or hardware stores for less than $5 a gallon... I did some quick math... and 1 gallon can EASILY take down 1000 gallons to 7 pH with well over half a bottle left over... let me double check that and get exact measurements for you tomorrow...


Well my experiment failed.

I did a floating raft with mesclun mix.
All red leaf and light green varieties could not grow successfully.
Darker green leaf ones technically survived but did not produce anything that could be considered a crop. Clearly the nitrate consumption of barely living specimens is negligible.

I'm glad I did such a small scale test instead of investing in something production size. Looks like I can't do AP without changing the Ph of my water, and that ain't happening.

Thanks for all your help. Now I know you can't do AP with lettuce at Ph 8.5!
The Master Gardeners have a saying: RIGHT PLANT RIGHT PLACE

I can tell you for a fact that there are plants that thrive at a pH of 8.5 (well according to the literature and testimony from many county residents).

More importantly, I have even read research for commercial applications where pH of 8 was used and no difference was determined in yield from the supposedly better lower pH of 6 (please note my use of 1 significant figure as I do not recall the decimal place of the numbers).

I will post a little more tomorrow, but please please do not give up hope! I think most of us here are reading this thread and thinking WHY DIDN'T IT WORK!!! Tell me a little more about what happened in the meantime, but there is NO reason why this shouldn't work!!!

urbanfarmer
04-30-2011, 08:38 AM
1 gallon of HCl @ 38% concentration weighs 9.901 pounds.
1 mole of HCl weighs 36.5 grams.

Weight conversion:
9.9 lbs * 2.2 kg/lbs = 21.8 kg

HCl weight conversion:
21.8 kg * 38% = 8.3 kg
8.3 kg * (1000 g / 1 kg) = 8300 g of HCl

Grams of HCl per Liter:
(8300 g / gallon) * (1 gallon / 3.78 Liters) = 2196 g / L [which is 2,196,000 PPM for the curious]

Moles per Liter:
2196 g * (1 mol HCl / 36.5 g) = 60 moles of HCl per Liter


60 moles of HCl per Liter

HCl is a strong acid, meaning that it will disassociate 100% in a solution. We also know the pH of a solution of 7 is 10^-7 moles of H+ per Liter. Therefore, 1 mole of HCl will lower 10,000,000 Liters of a solution of pH 8 or high to roughly pH 7 (roughly meaning +- 0.1 pH).

So, for 4000 Liters we would need roughly...

(1 mol / 10000000 L) / (4000 L) = 0.0004 moles of HCl

(0.0004 moles of HCl / 60 moles of HCl) = 6.7 x 10^-6 % of 1 Liter or 6.7 mL of the solution per 4000 Liters (roughly 1000 gallons)


So, for every 1000 gallons add 6.7 mL of 38% HCl (Muriatic Acid). If your local store only carries 10% use about 25 mL of 10% HCl (Muriatic Acid).

Please review this acid safety before beginning any work unless you are a professional: http://www.flinnsci.com/sections/safety ... TY_ART.pdf (http://www.flinnsci.com/sections/safety/chemicalSafety/L1040-1041_HS_LAB_SAFETY_ART.pdf)

SAFETY GOGGLES AND GLOVES ARE A MUST. I do not work without these, at a minimum (depends what I am doing).

10% is far safer and more commonly available, but still observe safety and caution. Always add acid to water and never the other way around (even for low concentrations). NEVER work indoors with this stuff unless you have a fully equipped laboratory to work in (again, even with low concentrations for safeties sake).

SPECIAL NOTES
A buffer occurs when a molecule has speciation at different pH values. This happens because the molecule might grab 1 hydrogen ion at one pH and as you move through the pH levels it might grab 2, or 3, or 4. The amount of speciation a molecule will exhibit is indicated by it's pKa value. This can be looked up and calculated easily, but you would have to know EVERYTHING in your water. A quicker approach would be to put just enough in the water to get the expected pH value and wait 24 hours. After everything settles, take another reading. From there you can adjust accordingly. For future reference, you will know what your system roughly takes to adjust if you have to do a full water change or you can calculate the volume ratios and have that on hand!

ECONOMICAL NOTES
$5 worth of this stuff will treat hundreds of millions of gallons. :ugeek:

DANGER TO FISH?
Obviously, HCl will leave Chlorine in your water, but the toxicity for fish is millions of times higher (in this case 10 million) than the concentration of Chlorine we are adding. Also, it will volatilize OUT OF THE WATER within a few days. No worries there.

Sample MSDS
http://www.brown.edu/Departments/Visual ... icacid.pdf (http://www.brown.edu/Departments/Visual_Art/documents/Muriaticacid.pdf)
http://www.sciencelab.com/msds.php?msdsId=9924285
It is unlikely there will be anything extra in your solution because HCl is VERY reactive. However, always verify with your supplier and check the MSDS or have us check it for you if you have any doubts.