Pond Boss
Posted By: Cecil Baird1 Small Scale DIY RAS 2.0 Intro Part 1 - 02/07/16 08:27 PM


I was asked to share this, and due to the fact that I've made some improvements since I first posted my system, I thought I would start another thread. I've gleaned various ideas and pieces of equipment off the Internet, and most of all my first and best source of info was Steven VanGorder's book Small Scale Aquaculture. The book is about $20.00 on Amazon and worth 10 X that much!

I hope the moderators and Bob don't mind, as I think this is something that can be of use to pond owners -- especially those of you that think out of the box, want to improve your options, and possibly save money on fish purchases.

From my experience the following DIY system works well for bluegill, yellow perch, smallmouth bass, and tilapia. I have no doubt it would work well for just about any other species of gamefish and forage fish.

I produce trophy size fish for fellow taxidermists after hatching in smaller specialized ponds, then the RAS for the winter, and then back to the larger grow out pond for the rest of their life span. All feed trained fish for faster growth.

A brown trout I raised sold to and mounted by Frank Kotula of Wilkes Barre, PA that won best in the world cold water fish at the World Taxidermy Championships in the professional division. Not reared in an RAS but the flow through pond on the property. Will be rearing trout in an RAS this fall however.


An example of a yellow perch and bluegill euthanized with an overdose of a fish sedative, removed from the larger female only yellow perch pond and male only bluegill pond. The fish are then frozen and shrink wrapped ready to be shipped all over the U.S. Minimum size for yellow perch harvest is 14 inches. Minimum size for bluegill harvest is 10 inches and 1 lb.




A very small niche market but in demand due to the fact in most states it's illegal to sell or purchase game fish taken from public lakes. Not so with privately produced gamefish, although there are a few southern states that don't even allow that -- except for pond stocking. Taxidermists seek trophy size gamefish for producing casts for the themselves and the replica market, showrooms, and state, national, and world competitions. I also occasionally mount up the fish for my own display or resale.

Some fish ready to be shipped by UPS.


My system would work great for producing or holding over tilapia in the winter for later stocking into a pond for algae control when temps are warm enough, or growing out small fish to be planted into a pond once they are large enough not to be forage fish. I.e. supplemental stocking of larger largemouth bass but the fish farm source of fish is small. I haven't reared feed trained largemouth in an RAS, but have no doubts they would do fine, and know of others that do it for the Asian food market.

What is an RAS?

First off, for those of you that don't know, what is an RAS? RAS stands for Recirculating Aquaculture System. In a nutshell it means reusing the water the fish live in over and over again up to nearly 100 percent (varies) by cleaning the water by a mechanical filter and a biological filter. It can get much more complex than that with additional equipment for large scale operations, but for the systems I use, that are small and DIY, that is pretty much it.

The advantages are water quality control such as temperature, oxygen, ammonia, nitrites, and nitrates, easy harvest of fish, control of growth, isolation from pathogens and parasites, and most importantly conservation of water.

YOY yellow perch produced in a hatchery pond ready to be brought into the RAS tank into the basement for the winter with a couple of smaller dead ones for comparison.




I've also set up systems for four high schools that are presently growing out tilapia to be sold for the algae control to a pond manager at the end of the school year.

High School system with RBC (rotating contact biofilter). Use a much cheaper easier to build moving bed biofilter now.
Posted By: sprkplug Re: Small Scale DIY RAS 2.0 Intro - 02/07/16 11:09 PM
Cecil, that is fantastic...thanks for sharing it with us!!
Posted By: Bob-O Re: Small Scale DIY RAS 2.0 Intro - 02/07/16 11:53 PM
I more than agree.
Thanks for this and I'm sure many ?s will appear. Probably gonna be a post for the archives.
Posted By: Bill D. Re: Small Scale DIY RAS 2.0 Intro - 02/08/16 12:08 AM
+1 !!!!

...BTW you might want to put more tape on that middle box before you let UPS have it! grin
Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/08/16 02:20 AM
Originally Posted By: Bill D.
+1 !!!!

...BTW you might want to put more tape on that middle box before you let UPS have it! grin


How did I know someone was going to comment on that? grin

As you can surmise what happened was I ran out of packing tape. So I was going to buy some on my way to the UPS terminal.
Posted By: highflyer Re: Small Scale DIY RAS 2.0 Intro - 02/08/16 07:44 PM
Okay Cecil,

Here are a few questions. I am asking to learn. I don't know if your way or our way is "better" and I would be willing to bet they are both very good and just different ways to grow the fish. With that said....

Are the bio-balls just to expensive for that size of a system? Or do the ropes do a better job?

What happens if the power goes out? Does the system have the ability to restart on its own?

How do you heat the water? And how do you replace the water lost?

How do you filter out the solids?

How do you drain the system?

Oh, more pictures please!!
Posted By: Bob-O Re: Small Scale DIY RAS 2.0 Intro - 02/08/16 10:04 PM
Overdosed....this rampant abuse of fish sedative must be curbed immediately!!!!
Why isn't this issue discussed in either parties political debates?
Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/08/16 11:20 PM
Originally Posted By: highflyer
Okay Cecil,

Here are a few questions. I am asking to learn. I don't know if your way or our way is "better" and I would be willing to bet they are both very good and just different ways to grow the fish. With that said....

Are the bio-balls just to expensive for that size of a system? Or do the ropes do a better job?

What happens if the power goes out? Does the system have the ability to restart on its own?

How do you heat the water? And how do you replace the water lost?

How do you filter out the solids?

How do you drain the system?

Oh, more pictures please!!



Brian,

I would prefer to answer your questions as I cover each topic. I'm breaking this up into sections to make it easier to digest.

But this question confuses me:

" Are the bio-balls just to expensive for that size of a system? Or do the ropes do a better job?"

What are you referring to with ropes? ???

This sections will be bottom drains, siphon, aeration, etc. etc.
Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/08/16 11:23 PM
Originally Posted By: Bob-O
Overdosed....this rampant abuse of fish sedative must be curbed immediately!!!!
Why isn't this issue discussed in either parties political debates?


Best way to go for fish! No pain and no thrasing!
Posted By: JKB Re: Small Scale DIY RAS 2.0 Intro - 02/08/16 11:50 PM
I would see, once all is said and done if a mod could stitch the different threads together. Make it one entire subject, kinda like a book with different chapters.

I'll have a number of questions as you go along. I have a few now, but I'll wait till you cover it first.

The bio-ball Q threw me a bit as well, but think it may have to do with floats that you see on some of the RBC rigs holding it up and in place.

I have a bunch of brand new bio-balls here if someone is interested. I think maybe about 6000 of one size and a couple thousand of another size. Had a couple cases of 2" degassing balls that I was going to mix in the smaller balls with for a degassing column, but NOT! Haven't seen them for at least 7 years. Must have grown legs.

Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 12:27 AM
Originally Posted By: JKB
I would see, once all is said and done if a mod could stitch the different threads together. Make it one entire subject, kinda like a book with different chapters.

I'll have a number of questions as you go along. I have a few now, but I'll wait till you cover it first.

The bio-ball Q threw me a bit as well, but think it may have to do with floats that you see on some of the RBC rigs holding it up and in place.

I have a bunch of brand new bio-balls here if someone is interested. I think maybe about 6000 of one size and a couple thousand of another size. Had a couple cases of 2" degassing balls that I was going to mix in the smaller balls with for a degassing column, but NOT! Haven't seen them for at least 7 years. Must have grown legs.





O.K. Got it now. Kind of slow at times. Thanks for clearing that up Phil.

I have three RBC's in the garage collecting dust. Even tried to sell them on the Aquaponics Yellow Perch forum with no luck. May use them in my coldwater system for a three staged biofilter.



According to two very knowledgable sources the RBC's are actually superior to the moving bed filters because they have more "usable" surface area. And they the can be gravity fed.

That said, to work well they need to be in their own tank which is a bigger footprint then the moving bed filter in a drum. At the schools I set up, space is at a premium. In my basement too. And mine would get quite a build up of mulm between the plates. I like
that the moving bed filters are self cleaning which keeps down anaerobic zones.

Also it's about $500.00 in materials to build an RBC unless you can find used fiberglass PVC roofing, and they are a lot of work to build. The moving bed filter is cheaper in materials and easier to build.
Posted By: highflyer Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 12:32 AM
Cecil,

Explain the RBC when the time is right. That was the question.
Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 12:37 AM
No worries just did.

Oh, the nylon rope was to support a tarp to keep the RBC dark. Didn't want the tarp to catch on the RBC as is the RBC rotated.

Got the bright idea to eliminate the frame on one unit and run the axle through the tank. That worked great until the water level in the tank dropped from evaporation and the rbc started laboring. Much better to keep the frame and allow the RBC to float on the water!
Posted By: Bill Cody Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 01:43 AM
Explain "mulm" buildup between the plates.
Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 01:46 AM
Originally Posted By: Bill Cody
Explain "mulm" buildup between the plates.


It's a combination of bacteria film and particulates in the water. More or less sludge.
Posted By: fish n chips Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 12:52 PM

Is the "mulm" good or bad, and why?

Not that important, but any Pics of mulm?
Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 03:30 PM
Originally Posted By: fish n chips

Is the "mulm" good or bad, and why?

It is if it blocks oxygen from getting to the bacteria as in between the plates of an RBC and anaerobic bacteria takes over. The bacteria you want is aerobic and is used to break down ammonia and nitrites. (To be covered later.) It can also plug drains and waterlines.


[quote=fish n chips]Not that important, but any Pics of mulm?


No but should have taken a picture a couple of days ago of some mulm that was blocking a vinyl water line from my clarifier filter to my moving bed filter.
Posted By: fish n chips Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 03:40 PM
So the "mulm" co-exists at the same area with the good bacteria? Anywhere "mulm" builds up(screens, lines, etc) does that mean a colony of good bacteria is there too?

And if so, when you clean it off. Then are you getting rid of good stuff too? How do you keep a good balance?
Posted By: Cecil Baird1 Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 04:02 PM
No, mulm is pretty much detritus and sloughed off dead bacteria that you're better off removing. This can smother and impede younger more active bacteria colonies.

That said don't confuse it with bacteria colonies in general. Being too clean and impede their growth or shear them off of surfaces.

In a typical RAS beneficial bacteria is growing on all surfaces. It's said up to 30 percent is on the tank walls, pipes, etc.

One of the advantages of moving bacteria filters that have media constantly in motion is the rubbing together removed the older and dead bacteria that grows on the outside of the media. This allows the new younger and more efficient bacteria to flourish.


Posted By: fish n chips Re: Small Scale DIY RAS 2.0 Intro - 02/09/16 05:21 PM
I guess I do need some pics of what a good bacteria colony looks like compared to bad "mulm". Sounds like it is important enough to know the difference.

When the "mulm" is cleaned off the moving bacteria filters, what becomes of it? Does it settle and eventually gets flushed? Or something else?

Thanks for helping to clarify this stuff. I have heard/read different things about "this" but nobody ever explained it really well, leaving it a bit ambiguous, probably because they didn't know themselves.
Posted By: derek_buck Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/09/16 09:04 PM
Originally Posted By: Cecil Baird1



Are these the blue perch color mutation?
Posted By: Bill Cody Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/09/16 09:14 PM
You usually won't see much good bacteria colonies as they are growing which are recognized by slippery surfaces underwater. As the colony thickens enough to easily recognize then it starts to become mulm.

Regular YP will sometimes have a bluish hue when grown indoors or in lighting conditions other than regular outdoors in deeper waters with natural foods.
Originally Posted By: Bill Cody


Regular YP will sometimes have a bluish hue when grown indoors or in lighting conditions other than regular outdoors in deeper waters with natural foods.


True! Mine even in the pond don't develop a rich coloration until about 13 inches. Then they develop a a rich yellow all the way to the belly like this one. My guess something in the wild diet that provides a pigment not present in the pellet diet.

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Posted By: JKB Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/10/16 01:51 AM
I've never heard the word "mulm" before.

I always thought it was biofloc.

Apparently to the Aquacultural Engineering Society, may be of some benefit. This is a bit interesting: https://www.aesweb.org/biofloc.php
I thought biofloc is suspended?
Posted By: JKB Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/10/16 03:03 AM
Could be. My memory from years ago is a tad off.

But, if it broke off your biofilter and was reintroduced into the culture tank in bite size pieces, would that be the same?

What I remember from an engineering book is the biofloc sloughs off the biofilter...
You guys are just getting me to wondering about more and more stuff confused

In my very simple system(s) that I have been experimenting with, I "think" I might be experiencing the benefits of what Phil has found in that link. Most of what is in that link is over my head, but the jist seems to be that what they call biofloc is beneficial(?). When my system builds up with what I will call "mulm" by Cecil's description, the water seems to stabilize, tilapia are happy. Then it eventually builds up so much it starts plugging lines, etc, and I clean it. However, I try to just clean sparingly because if it's done to much, the whole water stability goes crazy for a while and takes some time to settle back in. When Cecil says he cleans his off daily, that caught my attention and wonder what I am doing wrong.

When cleaning sparingly, I have always thought I was getting rid of "good bacteria" and this was the problem. Could it be that this substance(mulm or biofloc?.. one and the same?) may be what is really helping things stabilize for me?
I think you're confusing uneaten feed and faeces with mulm and bacteral film. The uneaten feed and feces is detrimental as it can go anoxic and produces competing heterotrophic bacteria. The bacteria you want is an autotroph and is aerobic. Unfortunately the heterotrophic bacteria multiplies much faster so you don't want to produce condusive conditions for it like a build up of uneaten feed and feces.

The mulm is neutral (except when it clogs pipes and filters), and the biofilm is produced by the bacteria to adhere to surfaces and protect the bacterial colony.

Over cleaning of an aquarium can elimnate the good bacteria but some cleaning is in order,
Posted By: JKB Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/13/16 03:28 AM
From what I understand, it's the same stuff.

A bunch of crap you don't want in your tanks or clogging up your filters or pipes, but if the fish in the instance enjoy it... Why not?
Nope not the same stuff. The feces and uneaten decomposing feed use oxygen and stink. They can also harbor pathogens. The mulm has an earthy more benign odor as does the bacteria.

Posted By: JKB Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/13/16 04:32 AM
Originally Posted By: Cecil Baird1
Nope not the same stuff. The feces and uneaten decomposing feed use oxygen and stink. They can also harbor pathogens. The mulm has an earthy more benign odor as does the bacteria.



Maybe so...

I was just going to let this go, because it might be steering the thread in a direction that it was not intended(?).

I think the stuff that I am experiencing is NOT unused feed or fecal. That stuff will not latch onto pipes, walls, etc... am I correct? I imagine unused feed/fecal material as to mixing/floating around the water or laying on the bottom. The stuff I have is attached. Sure it can break off and then float around, but for the most part it is attached and looks moss like, or hairy. I then assume this is mulm(?). You mention that the feed/fecal material can create a "producing heterotrophic bacteria". Does that stuff attach to objects, particularly attach itself to the good bacteria? Or is it distributed thoughtout all the water?

If I understand this correctly, you can physically see a good bacterial colony much the same as you can see mulm?.... Can you also see biofilm in any way?
Posted By: JKB Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/13/16 07:33 PM
The stuff I'm talking about looks like nasty snot. Like a Camel with a cold. It was collecting in the solids filter, but I had filtration before the biofilter, so it never got that far. A biofilter "in tank" would collect the same stuff.

Yes the biofilm is slimy and usually clear and somewhat snotty looking. It's the bacteria's way to adhere to surfaces and for short time keep it from drying out if it's exposed to air.
Posted By: JKB Re: Small Scale DIY RAS 2.0 Intro Part 1 - 02/19/16 10:54 PM
Yucky stuff was in the solids filter with uneaten feed and fish poo.

That's where it should get captured before it moves on to infect... and cycle thru the rig again, only to break down further.

Gotta clean them on a regular basis tho.
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