Backyard Aquaponics
A place to discuss aquaponics

Hi folks, this school year I was able to start an aquaponics class at the school I teach at. I am having the students keep logs and documentation of our process. We are just finishing constructing our systems. I have 2 sections of it and am having students keep a blog of our progress. See this link and check it often as they should be updating it often.

http://www.aquaponicsperiod4.blogspot.com/

I'll post the other classes blog when I get the address.

Gregg

here's the second blog link

http://mpiap1.blogspot.com

gregg

They are doing well, you can unglue pvc joins by heating them up.

We have fish! A friend gave us some koi. Tilapia is on its way. One of the blogs have been updated.

I think we're already cycling, I rinsed out a fish tank filter into the water hoping to jump start our bacteria.

System 1: pH 7.2, ammonia .35, nitrite 0, nitrate 0.25
System 2: pH 7.6, ammonia 0.45, nitrite 1, nitrate 10

So far so good, only 2 fish deaths with the transfer. Hung some flourescent plant lights, students are super into this class.

Some topics we've covered, plant diseases, fish diseases, deficiencies, system components and lighting. I think their next big project is create a business model for the school. What it costs to operate a system and how viable it would be to make $.

Whao, system 1 hit 1.5 mg/l of ammonia today. Yikes. we'll let it go and test again tomorrow and see if a partial water change is needed.

We're concerned because we have 140 gallon tank (50 small koi) and 52 gallons of GB space with only seedling in the GB. We might have to add more grow space or something. But our system is still very young so we'll see...

Nitrites hit 5 today in one system. Surprisingly only 2 fish died. Others look great. We did a 5-10% water change and aeration is going strong.

I had another thread in the plants section about curling seedlings. We surmised that it was waterlogging. It was cause once I started cycling early this morning, I can already see some improvements.

Gregg

Nitrite poisoning is deadly to fish HN.... but can be mitigated by "salting" the system....

Unlike disease treatment, which requires 3ppt+ of salt (a level that can impact on plants),.... you can salt for nitrites at about 1-2ppt....

yes, 1-2 ppt of salt in a system is generally simply good for fish health and will help with the nitrites. When levels get that high, no feed!

As to the grow bed space, yes you probably do need more. Having about as much grow bed as you have fish tank is usually a good aim for systems that will not be too heavily stocked or fed. That would be a 1:1 ratio and you usually don't need a sump tank for that.

Are the beds you have flood and drain?

Good learning experiences for the kids, great stuff!

http://www.happykoi.co.za/1.%20all%20about%20koi%20and%20koi%20keeping/removing_ammonia_using_air_aeration.htm

I quote "A recent study has show that up to 50% of ammonia can be driven out of a pond within a 48 hour time frame using nothing but vigorous aeration. "

May be helpfull while cycling.

Thanks folks. Its been fun and great to see the kids work so hard.

Our nitrite levels are still high and fish are starting flash and look unhappy.

What do you guys suggest? I will continue with some water changes and no food.

How does this salt thing work? Can you guys give more details on how to do so? I'll look it up some more too.

Thanks!!

Ooops yes we are flood and drain.

pumps run 30 minutes on, 1 hour off with a slow drain.

1kg of salt per 1000 litres of water = 1 ppt.

You want 2 - 3 ppt of salt, and as much aeration as you can.

It looks like a lot of salt, but it makes a big difference.

Thanks all. We added 1ppt of salt for starters and see. The fish are visibly happier, they don't cower in the corner anymore. We test nutes daily so we're keeping an eye on this. I have 2 questions for you folks.

1. Does the salt help the nitrite levels or just help the fish protect themselves? If it does lower the nitrite levels, how does it do that?

2. I want to add some pipes/gutters to grow plants in our system. We're probably going to get some PVC sewer pipe and make holes, fill with gravel and grow plants. Can anyone point me to some links or helpful threads? I tried to search. I'm specifically looking for pump cycling. Are pumps run constantly in these grow pipes? How high should the water level be? How do plants get oxygen?

Thanks folks!

The salt just helps protect the fish a little from the high nitrite, it is actually the chloride ion that does this.

I'm not entirely sure that this analogy is a good one but you might think of nitrite poisoning of fish being akin to Carbon Monoxide poisoning of people. It is a respiration thing and affects the blood's ability to take up O2.

Don't feed at all till the nitrite gets way below 1 and then when you do, feed very little. Keep up with the partial water changes until that nitrite does get down to or below 1. Then monitor levels. The Nitrite spike part of cycling is often more difficult than the ammonia spike part of it and does tend to take longer to get past.

Here's some nute data.