New System Questions

[Roger & April Frederick]

Hi Everyone!  We have started our system and have a few lingering questions.  We are running a Chop II style system with the following componants:

1 250 gallon IBC fish tank

2 sump tanks (each is 1/2 an IBC)

2 36"x45" media beds filled with 1/4" river rock (no limestone per vinegar test)

1 5 gallon swirl filter

2 10.5' x 2' raft beds (being built)

air pump is on the way

we are collecting and sterilizing plastic bottle caps to float in the sumps for added bio filtration

1 small, mechanical sediment filter on the submersed pump and small filter pads at each media bed outflow.

We filled with our untreated well water and have been fishless cycling with clear ammonia for about two weeks and have some seedlings started in the media beds.  Testing with the API master kit we have a pH of 7.6, no amonia, no nitrites, nitrate levels fluctuating, average water temp ~80 F.  ?

So, the lingering questions:

How many fish can the system support?  (we're still debating over bluegill or tilapia)

When are we definitely ready to add fish to the system?

Can we put the fingerlings directly into the IBC, or should they grow in a small tank until the reach what size?

Do fingerlings require a different diet from adult fish?

We've started feeding the seedlings with a foliar spray of Maxicrop, but can/should we be adding that to the system itself in addition to the ammonia?  

How do we continue to manage feeding plants until fish are large enough to produce adequate food for them?  

Any other advise you might have based on the info above is also greatly appreciated!  :)

[Lonnie Kirkman]

smaller tilapia grow better on a High protein high fat were older tilapia still about 32-36 perct. protein and 6-7 percent fat and the number of fish when there small you can have alot but when they get bigger I have to adjust my numbers so my Levels stay good I run my systems with 100- 130  fish work well when there about 4 in long I run more when there smaller and then I split them up you have more grow area than I do  if you start with 100 about 1-2 inches watch your Levels and if there real low you can always add more fish

[Ron Thompson]

There are others who can answer most of your questions better than I but here are a few answers:

- we're still debating over bluegill or tilapia

  If you are north of Orlando, one thing to consider is the need to heat water in wintertime. Tilapia can not go very low in temp. They really need to be in the high 60's/low 70's to continue growing. Most times that means an electric heater which can be costly to run. Bluegill do not have that issue (neither do channel cats or trout - but trout don't like high summer temps). So consider where you are in making a decision.

-- you can add maxi crop directly to the system. Since it will recycle it does not need to be as strong as the bottle says. My fish generally don't eat for a day or two after adding it, then they go back to normal. I've never lost one though. You should also be using the Maxicrop with iron since that is generally missing from aquaponic systems.

- fingerlings eat the same but need smaller size pellets. I use 1/8" for all my fish; the big ones just eat more of it. If you have really small fry, just grind some pellets in a blender or coffee grinder to make it a corse powder.

- the maxi crop will feed the plants until the fish can sustain it.

A couple things I learned the hard way:

-- redundant air pumps on separate circuits. If one goes out the other will save your fish.

-- If you have a pump in the fish tank, put it in a bucket or container. If your return flow goes bad, the pump will only draw down to the top of the bucket. That leaves a foot or so of water for the fish. Without the bucket you can draw all the way to the tank bottom leaving your fish high and dry.

--always plan for expansion. If you think two valves will do it, get four. If you think a 1" line is sufficient, get a 2" line. You will save money and effort in the long run.

--plant something strange, it is fun to grow something no one else is. I've got pineapple going in my setup (easy, just buy a pineapple, cut the top off about an inch into the fruit and stick it in the media bed. Eat the rest of the pineapple. Don't like pineapple? so try something else, nothing to lose.

MOST IMPORTANTLY

always remember - this is suppose to be fun, so enjoy yourself.

[Roger & April Frederick]

Thanks so much, Lonnie!  I figured the younger fish would have slightly different nutrition needs.  Are you using commercial pellets?  I'm wondering about using duck weed, as I've seen mentioned, but wonder if it meets all of the fish's nutrient requirements.  

Lonnie Kirkman said:

smaller tilapia grow better on a High protein high fat were older tilapia still about 32-36 perct. protein and 6-7 percent fat and the number of fish when there small you can have alot but when they get bigger I have to adjust my numbers so my Levels stay good I run my systems with 100- 130  fish work well when there about 4 in long I run more when there smaller and then I split them up you have more grow area than I do  if you start with 100 about 1-2 inches watch your Levels and if there real low you can always add more fish

[Roger & April Frederick]

Wow Ron, there is so much helpful into in your post!!  We are just south of Brooksville, so have been leaning towards bluegill.  But, I'm concerned about depending upon commercially available feeds as I can't be certain what is in them. I don't know how much additional effort is required to grow enough worms or fly larva to keep them fed.

We've tried very hard to keep future expansion in mind knowing that once we get going this is likely to be so much fun we'll want to do more.  I'm sure we'll find many, many things we should have done differently.  :)

RE: maxicrop, I'm having trouble figuring out how much I should add to the system.  The bottle gives me info directed at plants growing in soil and I'm not sure how to go about extrapolating that for my hydro system.  Do you know of a good resource I might go to for additional information?

Ron Thompson said:

There are others who can answer most of your questions better than I but here are a few answers:

- we're still debating over bluegill or tilapia

  If you are north of Orlando, one thing to consider is the need to heat water in wintertime. Tilapia can not go very low in temp. They really need to be in the high 60's/low 70's to continue growing. Most times that means an electric heater which can be costly to run. Bluegill do not have that issue (neither do channel cats or trout - but trout don't like high summer temps). So consider where you are in making a decision.

-- you can add maxi crop directly to the system. Since it will recycle it does not need to be as strong as the bottle says. My fish generally don't eat for a day or two after adding it, then they go back to normal. I've never lost one though. You should also be using the Maxicrop with iron since that is generally missing from aquaponic systems.

- fingerlings eat the same but need smaller size pellets. I use 1/8" for all my fish; the big ones just eat more of it. If you have really small fry, just grind some pellets in a blender or coffee grinder to make it a corse powder.

- the maxi crop will feed the plants until the fish can sustain it.

A couple things I learned the hard way:

-- redundant air pumps on separate circuits. If one goes out the other will save your fish.

-- If you have a pump in the fish tank, put it in a bucket or container. If your return flow goes bad, the pump will only draw down to the top of the bucket. That leaves a foot or so of water for the fish. Without the bucket you can draw all the way to the tank bottom leaving your fish high and dry.

--always plan for expansion. If you think two valves will do it, get four. If you think a 1" line is sufficient, get a 2" line. You will save money and effort in the long run.

--plant something strange, it is fun to grow something no one else is. I've got pineapple going in my setup (easy, just buy a pineapple, cut the top off about an inch into the fruit and stick it in the media bed. Eat the rest of the pineapple. Don't like pineapple? so try something else, nothing to lose.

MOST IMPORTANTLY

always remember - this is suppose to be fun, so enjoy yourself.

[Ron Thompson]

I'm just outside Inverness and must heat the water in winter. When my Tilapia are gone I'll be going to Bream (Bluegill for our Northern transplants) and continue with Cats as well. I've toyed with the idea of putting in some blue crabs but they won't breed in freshwater, I may still just as a holding tank for dinners. 

Where you are, you would still need to heat water in winter to get any growth out of your tilapia.

As for Maxicrop, I was adding about a quart a month to my tank but likely should have done it every two or three weeks. I didn't get much change in results so dropped it. It was costly in any case for what it did. I've had better results with fish water and a pint of chelated liquid iron once a month.

Let me say this again - oversize your plumbing. The only reason I'm answering right now is I need a break from the heat. I've been switching out my return lines to double the flow rate. Even doing that I wish I could triple the size but have no way to expand to physically fit it into my setup. If I had done that when I built it, I would have saved a bunch of money, a bunch of time and definitely a bunch of sweat. Yes, 3" line and fittings are costly, but it will save a huge headache later.

As much as I enjoy this, today is one of those times when I think I should have just bought my veggies at Publix and shut up. 

If you find yourself up in Inverness, let me know and you can look at my modest setup. I'm sure you'll get ideas both to incorporate and to avoid.

[Lonnie Kirkman]

I agree if you dont want to heat the water bluegill will be a good selection I have Tilapia right now and I have a 120,000 BTU propane pool heater on my pools

[Roger & April Frederick]

Thanks so much for your input. I'm a little worried about the water temperatures, but think I'm still going to try the Tilapia.  As long as I can keep them from dying from cold stress, I don't really care much if growth rates are slow.

Ron, hope the plumbing went well.