Fishwater in hydroponics?

[Burton]

So I was thinking the other day about my future system and was wondering if anyone has tried this and if my concerns are founded or not.

 

So the idea would be to have two or three systems to use all the space I can in my home. The bottom level will have the aquaponics system, and the upper floors will have two hydroponic systems. But I really don't like the idea of having to "add" chemicals to water as food, iron and ph adjusters I can justify.

 

So the thought process was to take water from the aquaponics system via the pump into a container and manually dump it into the hydroponic systems up stairs while taking the "old used" water down stairs to the grow beds.

 

So here are my thoughts

• The "food" would not last long enough and would require more than two trips a day
• The returning waters PH could be really messed up and affect the aquaponics system ( not as worried about this )
• The 300 gallons I plan on using might not be enough to feed my 26 sq ft of growth beds and the hydroponics system (mainly drippers to reduce waste getting caught in a "sprayer" type system)

Anyone try this before?

[TCLynx]

Well, sounds to me like it could be a fair bit of extra labor involved.  Also, any system is going to have to find it's own "balance" and what will work for you.  If you were to stock the aquaponics very heavily and remove the solids to digest them in one of the hydroponics set ups, that might be a  way to do it.

In any case, you are not going to find any currently existing set ups to "perfectly" model your system after.

 

26 sf of 1 foot deep media beds is not enough to support a 300 gallon moderately stocked aquaponics system without solids removal and 26 sf of raft will support far less fish without solids removal and extra bio-filtration.  (put it this way, the Friendlies low density micro system is only designed to support about 19-20 fish of up to maybe one pound each in a 300 gallon fish tank and it uses 64 square feet of raft bed.)

 

So once you are well cycled up, I think you can support more plants than just your 26 feet you mention.

Would it require more than two trips a day.  Well depends on if you are just moving water or if you figure out some sort of digester that could take solids and slowly break down and feed the plants.  Moving solids to another system once a week might be easier but you would have to design the digester that would work for you.

 

I would advise against even drippers.  Bio-slime will clog even 1/4" tubing with no restriction on it.  Figure out your hydroponics systems so you don't need to use any restrictive devices on the flow if you can.  This is one reason why flood and drain or DWC tend to be so popular for aquaponics, less clog cleaning.

[Burton]

I plan on starting with few fish anyway, till I notice the plants cant get enough food. But I didnt think about the clogging ... might just have to bite the bullet and have a separate HP system too >.< ... wonder if a 1/2 pipe on a timer would be a better option to deal with the solids ...

 

26 sqft is the minimal, got this number based of the excel sheet here http://www.aquaponic.com.au/backyard.htm. Currently the system will most likely end up being 29-37 sqft given the extra bed I would have to get to cover the 26 sqft number. All depends on the stock tanks I get.

 

So what would the same 20 fish per 300gal require in a MB system do you think? I will most likely end up with koi or goldfish given I dont eat fish.

 

Need to know these things early so I can plan the layout more than anything, like you said I can always add more beds if needed. The lighting system I am making will support up to 48 sq ft of grow beds so any advice is good advice especially when it comes from someone with experience.

[TCLynx]

There is an artificial lighting group that you should go to for help figuring out the lighting.  I'm spoiled by doing my AP outdoors under the sun.

 

If you are running very minimal fish (and if you feed them something like aquarium goldfish food) you may have trouble keeping plants happy.  However, if you feed a good high quality feed meant for growing fish, then it can be very easy to have plenty of nutrients if you leave the solids in the system.

 

With my catfish when they are eating well, 20 fish in a 300 gallon stock tank were easily able to keep my 600 gallons of deep grow beds in plenty of nutrients.  Unfortunately, I don't know the exact square footage of my beds since they are stock tanks.  They are deep though so it is probably about half the square footage of plant space as a similar volume of just 12 inch deep beds.

 

Luckily with koi or goldfish, you can start and expand as you see what the system does for you.

[Burton]

100 gallon rubber made right? how many inches from the top do you fill them and how many do you have 6?

[Burton]

 [ 1438" X your growth bed depth (take 24" - space above bed you did not fill) ] / 1728 will equal a rough but close sqft for your growth beds then multiply that times the number of beds and BINGO good estimate :)

 

Its going to be slightly larger than what it really is obviously :) ... Or if you know how many bags of 50L hydroton it took to fill them all you could figure out grow area.

 

( Bags / 3.7854118 liters ) / 7.48051945 US gallons = sq ft

 

 

[TCLynx]

I fill em pretty much right to the top. 

I'm personally not that interested in exact square footage.  I don't measure my feed by the gram and I don't weigh my fish to figure out how many grams of food I should be feeding week to week as my systems are "backyard systems", not commercial.  I feed the fish, harvest some plants, eat some fish, sprinkle some seeds, occasionally buy more fingerlings.

I try to design systems such that the filtration is plenty robust to handle some neglect since I'm not home on a regular schedule to baby it along sometimes.

[Burton]

UPDATE:

Ok funds are in and I was going over my potential layouts again and noticed a flaw.

My preferred setup would be a 275 IBC bisected and placed over top a 300g Rubbermaid tank with an indexing valve on my 15gpm pump to flood one bed at a time ... see the problem yet?
123 gallons out of a 300g tank would drop its water level by about 10" over 10 minutes in the FT ...

So an obvious solution would be to reduce the amount of gallons being pulled out of the FT at once ... But just how much should I aim for in a water level fluctuation and can I get away with not using a sump?


If I used a 12" fill line on the bisected IBC instead of the 18" above then I would be using about 83 gallons @ 31.1 cuft total GB volume or ~233 gallons (so I would need to add say a Ziptower to the mix for proper filtration no big) With my current pump it would take 5m15s to move 83 gallons of water only dropping the FT level about 6/7" ... Is this acceptable?

Or should I be aiming to purchase a separate 100g sump and another pump?

 

Stock rate will probably be 14ish Shubunkin or Sarassa Comets (max length around 10") since I don't plan on eating my fish. Most similar to koi in they produce a lot of waste.

 

 

Suggestions expected and welcome :) If you need a visual of the space involved I can whip one up in a couple of seconds.
If you look at my pictures you will see on the first floor the 11 x 8 space is my preferred location because it has a in-wall heater, two windows, and two air vents in the ceiling for climate control if I decided to erect movable walls this location would be best. There is also two outlets and a ceiling fixture I will be converting to an outlet.

 

[TCLynx]

Well if you are only stocking with aquarium kinds of fish, they are fine in only 10-12 inches of water so I see no issue with letting the stock tank fluctuate with such small fish.

In general if you are talking a total of 275 gallons of grow bed while using a 300 gallon stock tank as fish tank.  You can flood that without much issue especially if you are going with small non food fish.  When the grow beds are full of gravel, it generally only takes about 40% of their total volume to flood them.

 

I've run with 3, 100 gallon grow beds hooked to a 300 gallon fish tank and I was able to flood and drain that without even using the indexing valve through the water level did fluctuate a little too much to keep large catfish happy.

[Burton]

TC you would find the most obvious thing I overlooked lol TY for that btw...

 

I forgot about the hydroton being in the GB nearly cutting in half the water required >./p>

So a IBC bisected would be 148 gal total to fill them both at once.

What is a "large" fish to you ? I know you have 5lb+ cats but I always thought of 12" fish being large, this coming from someone who's biggest FT in the past was 55gal however :)

So I should aim to flood and drain both IBC halves at least two times an hour to get the complete 300 gal through the system correct?

 

 

[TCLynx]

Well you could flood twice an hour or you could simply let the pump run long enough during a single flood to move the desired amount of water.  The excess flowing down the tops of the stand pipes are still getting filtered and aerated.

 

So you have a choice, of running the pump for 25-30 minutes once an hour or running for 12-15 minutes twice an hour to get the flow and filtration.

 

A 12 inch fish is fairly large.  I suppose it just depends on the disposition of the fish as to if a water fluctuation in a relatively shallow fish tank (since stock tank fish tanks are kinda on the shallow side) is going to stress them out I guess.  Channel catfish are kinda high strung easy to stress out fish.  I don't know the types of fish you are planning that well so I'm not sure how mellow or high strung they are.  I was figuring that the comets would be able to handle shallow water and will probably get to the point of letting you pet them while feeding so I wasn't worried about them and a little water fluctuation I don't know the others.

[Burton]

Is there an easy way to tell if they are going to be stressed?
I have been looking on line for anything related to the topic with these two fish and have not turned up anything. >.br/>I imagine if they didn't like the water level getting lower they would start darting around in the tank every time the water level dropped X amount correct?

 

I don't mind using an indexing valve if it will reduce stress on the fish as they are fairly cheap given their usefulness ... and if it means not getting a sump then it is a better option for now.

[TCLynx]

I'm not sure how to tell if a particular type of fish will be easily stressed.  I know channel catfish can be skittish creatures while tilapia seem to handle all sorts of horrible things as do many types of goldfish.

 

But, if you are online now, you might go check in with JT The Aquaponics Garden Monday Night Chat

As He would be your indexing valve Distributor and he could chat with you about the options.