Backyard Aquaponics
A place to discuss aquaponics

I've used the search bar but most everyone speaks on media filled beds and I'm wondering about NFT.. I've read a general rule of thumb is 1:1 fish to plant -50 fish.. so if you had 500 plants you would want 450 fish.. this may be horrible advice but I've been told in person it was a good ratio and I've read it on a different forum so I'm wondering if that's sound advice and if it isn't what do you suggest?

I'm also wondering about my system specifically.. I am hoping to get pics up in a while but I'm very busy atm. Picture fish tank-->swirl filter-->water trough-->back to fish tank.. If you guys can picture this set up based off of that ( probably not ).. will this be enough for long term filtration? I've heard swirl filters will only get big solids out but there are other smaller "solids" and bad stuff to get out before re-pumping back into your fish tank.. Is there any methods people use after swirl filters like very tight mesh or some other material to get out smaller solids? I'm thinking I could add some kind of mesh material at the point the water is coming out of my swirl filter into my "water trough"..



I attached an aerial view of what this part of my system looks like.. the white lines in-between each container are PVC pipes and it's a very minimal simplistic sketch.. this is just to give an idea of what I'm working with.. the fish tank is 400-500 gallons.. the swirl filter is a 55 gallon barrel.. and I don't know how big the trough is.. I'm sorry I'm typing this before I pass out.. I've been up 24 hrs now.. working on this.

Been a lurker for 3 years.. never posted.. hello backyard ap community.. nice to have my first post!

the reason we use media is because it provides Bio-filtration!

if you want to use DWC or NFT you will need expensive bio-filter media and maybe mineralisation and degassing tanks.

Welcome

Welcome to the forum.


Not at all what I would suggest. First of all how big are the fish and what sort of fish? Obviously small fish produce less nutrients than big fish but another issue would also be the species and your climate. If you have SP then for a good portion of the year around here they wouldn't be eating anything so the number of plants they would support over winter would be stuff all. Conversely with trout you could support lots of plants because they would still be eating like made and the plants wouldn't be growing very fast.

Second the nutrient appetite of lettuces and tomatoes are kind of different.

As has already been said if all of your plant production is going to be NFT or DWC you are going to need more filtration than just a swirl filter.

Sorry I didn't offer any alternative guidance.


If you are going to remove the solids from the system then your best bet is to model your ratios on the UVI system. That will give you some idea of plant to fish ratios. Just google "UVI aquaponics". You will get heaps.

Hey I'm just now able to get back to my computer. That was my fault for not providing more info lol sorry.

I'm in the southern U.S. with an average temperature of 89F (32C) in July which is our hottest month and the lowest we get on average in January is about 25F (-4C).. I will more than likely be growing Tilapia and leafy green vegetables only. Different Lettuce varieties, Kale, Spinach, Herbs, Arugula, etc.. Also, the roots won't be completely submerged in water and instead of a "trickle" or "stream" of water like most NFT systems, I will be misting the roots..

I'm not familiar with re-mineralizing or bio-filters but I read where you can use your solid fish waste to act as a bio-filter? maybe I'm wrong or misinterpreted what I read but can anyone shed light on the mineralizing and bio-filtration aspect and if it's truly needed? I'm about to google UVI aquaponics as well.. thanks for the suggestion Stuart.

I've also read that 1 fish per 5 gallons of water is a good ratio. Is this correct?



Main information that should be noted:

-Average Temperatures:
-89F (32C) in July which is our hottest month
-25F (-4C) in January which is our coldest month

-I WILL be growing in a greenhouse
-30 feet (9.1 meters) by 50 feet (15.24 meters)
-Tilapia & Leafy Green Vegetables

I deleted my "paint" picture that I drew up detailing my system.. it was more of a distraction and not accurate.. I'll just try to discuss what it is through text if people need more info..

so essentially the reason a bio-filter/mineralization tank is needed in DWC and NFT systems is because you are without grow beds? Can you not throw in a grow bed that would work in your system (obviously the size would need to be right) as a bio filter/re-mineralizer? Maybe you could incorporate tomatoes or other plants that can't grow in DWC or NFT systems as well..

So you add a grow bed that grows tomatoes (then you just added a crop that you normally wouldn't be producing with DWC/NFT) and throw some worms in the bottom of it.. and boom you have a bio-filter? lol.. would this solve the bio-filter and re-mineralizing in DWC and NFT systems?

Yes plenty of AP systems use media filled GB's to "filter" the water before a DWC and or NFT.

...but you have to size the GB accordingly. The primary function of GBs is not to filter solid waste or to act as biofilters rather it is to store the solid wastes and process them into nutrients. This takes time which means that the beds have to be pretty large because there has to be enough room to hold the solids while they are being processed.

MT on the other hand only processes solids to a minimal degree and due to the extra energy that is pumped into them by aerating them the tanks can be relatively small.

Each option has pros and cons so you have to choose what overall option suits you best.

Ok so GB's and MT's essentially do the same thing..? GB's are just a more passive way to get things done while MT are more intensive as far as energy and work?

GB's are more passive as far as energy is concerned but they allow you more area to grow produce..

MT's are smaller in size and don't allow any extra growing area, and will cost more as far as energy consumption (aeration/pumping)

Would everyone agree that GB's are all around a better option for keeping things stable with less work? I'm sure the initial purchase of hydroton would be quite a bit of money vs. the MT but hydroton and most other GB media lasts awhile correct? I'm not too familiar with GB medias.. I know there will probably be one day full of torturous cleaning or "maintenance" on the GB and media and that probably wouldn't be needed on a MT but if you were to add worms and grow more plants in the grow bed it seems like it would be a more "natural" cycle like what would automatically occur in nature..

Well sort of do the same job anyway.

That is my understanding although it does depend on the GB design. I've never used a MT but one of the reasons is that the research papers I've read conclude that they are more energy intensive. Ryan has challenged this saying they don't use much energy but then he hasn't provided any comparative data.


Are you kidding? Of course not. I think for BYAP they are the best option pricesly because they are less work, more stable, more reliable, more ......etc. As long as they are not overfed. Then they clog and cause you all sorts of problems.


Hydroton or the equivalent is expensive but is very easy to work with and lasts a long time. Gravel is cheap but much harsher on the hands.

I think I cleaned one wheel barrel of gravel and then said "this has got knobs on" and didn't do any more. To justify that approach I believe that the rock dust is an important source of trace elements Scoria can come of the truck VERY muddy but the quarry that I'll be sourcing mine from in future sells washed scoria of many different grades. It will still turn the water muddy at the start but its not that much to fuss me.

If I do the GB's it would be about 5 55-gallon drums cut in half resulting in 10 grow beds in one 30 foot long line.. If I'm doing my math right it would be about 50-60 gallons of fish tank water per 10 feet of grow bed every hour.. (1 full cycle of fish tank volume per hour is the gold standard right?)

and when I think of gravel/rock dust I just picture more ph problems instead of harder on the hands .. but I guess both are negatives compared to hydroton. I think I might invest in the hydroton..

and to address the mineralization tank I feel like if you are adding a pump/air stone to keep it running 24/7 or close to it there is no way that doesn't add up.. a grow bed gives you more production also.. so you're saving money on energy costs but gaining a little more work every time you need to clean your GB's BUT gaining a 30 ft long by 2 feet wide grow bed for more income.. I know which one I want lol

sorry im a little late to this thread.. but why not the bottom half of the grow bed lava rock and the top the white round decorative granite? other than weight? a fill them with worms?

Nothing stopping you.

I had blue metal with about 6" of 3-5mm quartz on top. It worked well and the quartz didn't get mixed in by the water flow. However, when pulling deep rooted plants out of the GBs they did tend to mix it up.