Backyard Aquaponics
A place to discuss aquaponics

Hello Dave,

What part of the system is the biofilter if the beds are only watered occasionally from the hose?

The grown beds are the biofilter. Problem is my plants are still to small to be effective. I planted the first of the beds on 25 November with seeds. I water all ten beds three times a day but that only lowers the water level in the pond about one inch per watering - two to three inches total per day. When the seeds germinate and the plants grow, then the plants will suck up the bad stuff (nitrate or nitrites - which ever the plants eat). Then I will also be pumping more water into the beds. It's just that the system is just starting out and not up and fully working yet. The water from the grown beds drains back into the pond. I also started yesterday watering my entire garden with the pond water so as to lower the level more each day. I would like to have to replace 3 to 4 inches of pond water daily.

I let the water hose run back into the pond 24/7 hoping that the splashing water will add oxygen. I also let the pump run water up a pipe about 18 inches above the pond and the water splashes back into the pond 24/7. However, I don't think that that is enough so today I will go buy an air pump and add it to the system.At present I only have 80 fish. I have 150 more coming, maybe today. My test kit is suppose to arrive today also.

The system and it's development are still in the developing stage. When I get the proper balance I should be ok.

Duinui

First the Catfish, then the Nin and Tab Tim, never found out why.

Surprises me - I have always thought that the catfish were the most hardy.

I plan to get an air pump today. So far I have lost 10 percent of the fish since 22 Nov. I got the 8th one this morning.

John,
The GB's perform multiple tasks, not just growing plants.
2 types of bacteria grow on the gravel/media.
The first converts Ammonia to Nitrite.
The second converts Nitrite to Nitrate.
The plants consume the Nitrates.

Ammonia is the most deadly to fish, small amounts will lead to problems and death.
Nitrites are not so bad, but still harmful.
Nitrates are virtually harmless unless in huge quantities.

You need to cycle the water through the GB's as much as possible in the beginning.
Recent trials at BYAP have shown that constantly flooded GB's cycle the fastest.
Cycling means development of sufficient quantities of both types of bacteria to remove the ammonia and nitrites, also by this time your seedlings will be of sufficient size to start removing the nitrates.

Pumping water into the GB's also adds air increasing DO levels.

One possible problem you are going to have is that using coco and rice husks as a sole media type is it will be too wet for the plants when they are older.

You might want to consider putting gravel in one or more of the beds.

Dui.

Duinui

What size air pump do you recommend that I buy for this pond? How big of a bubbler or air stone do I need?

I have on hand a small air pump that we used in the koi pond and attached six round stones (tennis ball size). At first it was fine but then the stones clogged up often and IMO the system was worthless.

I just received 320 fingerlings and put them into the pond so now I have a total of 392 live fish thanks to wife and brother in law. I only ordered 150. No test kit yet. Seems hard to find in this area. BIL took a bottle of water with him to have tested tomorrow. Maybe that will give me some help.

You might want to consider putting gravel in one or more of the beds. I had thought of that but then how do I grown vegies in there, for sure not from seed, maybe transplants. Then I think I would need a flood and drain system to water with. A constant flow of water would be too much for the plants.

The BYAP Trials.
A long thread, with some surprising results, especially regarding constant flow.

Yes you can plant seeds directly in the gravel, that is what most people do.

I don't know what size air pump to recommend, a big one

You might find water test kits in decent aquarium shops, they were hard to get in Surin too, many of the shops only stocked PH tests, but they will probably order the others for you.

The girl at the Ministry of Fisheries said she couldn't test DO reliably with bottled water, but the other major params are important too, please post when you get them.

I use an old scrubbing brush to clean the crap off the airstones, seems to work ok.

Duinui,

I have two gravel bog gardens I use to filter my koi pond. The water is pumped into the bottom of the beds and rises up through the gravel and overflows back into the pond. Water/pumps run 24/7. The water was fairly clear until my wife overstocked and we let the koi get large. Then I had to buy and install a bio-filter to help out. The water is as clear as a glass of drinking water. The gravel beds are 12 inches deep and filled with 3/8ths pea gravel (expensive stuff inland from the river). All of the plants where a few inches tall or more when planted and grow like hell. So I have thought of raising veggies in gravel - I just need more education on the subject. The system I am using for my grow beds and pond now is what I learned from a friend of mine here in Thailand. This is a first year thing with it and I am learning.

On growing from seeds in gravel. How do you keep the seeds from just washing away? Am I correct in thinking that I would have to use a flood/drain system with a timer to grown veggies in gravel? I know in my bog gardens you loose the beneficial bacteria if the gravel dries out and you have to start over. I have thought of adding a set up like this to what I have now.

I have to go shopping again tomorrow. I still need a test kit and an air compressor. Do Home did not have what I needed. No kit and their compressor was only large enough for a glass tank.

In AP we generally pump water into the GB's from the top.
Then, by various different methods, flood the bed to maybe 1 inch or more below the surface of the gravel.
Some beds remained constantly flooded like this and again by various different methods, the water overflows back into the sump/fish tank whatever.
Flood drain is what many/most do, siphons, timers etc. etc.
I think you might need to go through some system threads, I know many of them are very long, but there is so much valuable information in them.
My last post I meant to give you a link to the BYAP trials, I think this would be a great place to start.
viewtopic.php?f=1&t=8621

Yes you are correct about gravel drying out killing the bacteria.

Keep the questions coming, there is a massive amount of knowledge and help available on this forum

I'm worried about your new fish, it sounds like the other system is ideal for what you need with the gravel bed. It's OK to use the occasionally watered setup to grow more plants, but a recirculating system is the usual main system and you definitely will want some part of that to be cycling all the time for the main biofiltration.

Dave,

I agree. What I am doing now is almost nothing compared to the filitartion going on in my gravel beds. Using a bio-filitration system as you suggest - would that leave enough nutrients for the plants? In my GB there is only rice hulls and coco coir, plant food is lacking.

John,
The whole point about AP is that the bio filter (gravel bed) converts ammonia (NH3 and NH4) into Nitrates (NO3) which _is_ the plant food.
Many people add other supplements such as Seasol (I haven't been able to source that in TL) but many others say they add nothing.
I've added nothing to my systems and not noticed anything other than slightly yellow leaves due to high PH.
But that is solvable by adding Chelated Iron, which is available here.
There is a supplier link on one of my threads, also a link to water test kits which I'll dig up later.

Duinui,

So far I have read up to page 28 of trials. I will finished it tonight, I hope. I have also read thru page 7 of your Surin thread. I did not know that you can grow veggies like tomato's in water. I always thought the roots need air and that that was the purpose of the F&D with the air coming inbetween. The water flows up thru the gravel and over it to the overflow in my gravel beds. It is moving all of the time. I am afraid the seeds would be moving too. LOL But as I read I may become interested in CF or a combination of the two systems.

Today I purchased an air compressor. Hailea ACO-009. I wanted the largest, the ACO 450 and the clerk and my wife went crazy. They use the 450 to run the whole store. It's the big fish shop on the corner of the highway next to Big C. I also bought a bio-filter 40L filled with some type of rock. The blue barrel looking thing. The filter will help out for now until I get my system up and running right or modify it. They also put some type of white fabric in there, like steel wool. I don't know what they call it because I have never used it before. That's my wife's department with the koi. Lost l5 more today since last night. The water management people said that the water sample tested ok, no problems. But they gave no specifics, numbers. Off to do my homework.

I think a lot of people were surprised with the results of the BYAP trials as far as CF is concerned.
My guess is that with the water so well oxygenated the plants don't mind their roots being submersed.
But that is nothing more than a guess.

I know that when I want to pinch a few worms from my GB's for fishing, they are always well below the flood level, there's enough oxygen for them, so why not the plants...

Hope your fish stop dying, it gets depressing sometimes, especially when the water tests are all ok.

Thai people belief that the new cement tank leach poison and usually make fish die.
Have you fill water for a few week (and drain) before bring fish into the tank?

Hi AO,

Yes tank was completed in August and we added expendable fish. They are still alive and multiplying like crazy. They just swim right along with the top teem. We filled the tank about two weeks before putting anything in it. My wife put is some waterplants and my mother in law threw in banana stocks and pieces. The banana stuff was in there for about two months.

The belief, I think comes from the fact that lime can leech from the cement and harm the fish. So far I have not had that problem. We just scrub the pond down before loading with water.

Any losses today John?