Backyard Aquaponics
A place to discuss aquaponics

Hey scotty,

I'm hoping there won't be any solids down at the bottom! If there are, then my iAVs system isn't working as I would expect. But I think you are right about it being oxygenated enough between cycles. I don't have a DO meter yet but one day...

Yeah, the clear tubing was a quick fix because for some reason black tubing is hard to find down here. It's underneath the system though so not too much light.

Just a little active volcano in the backyard? Lol Costa Rica looks spectacular. Super envy. If Trump gets elected you may be seeing a lot of Liberals heading your way, us included.

You're welcome to come on down even if Hillary gets elected... Seriously a real estate guy I know says things really pick up every election cycle -- it doesn't matter who wins, it is almost always the same, he gets a BIG boost in sales queries. Good thing for us not very many really follow through on the threat to leave if so-and-so gets elected. The fatal flaw that many who try to live in a foreign country hit is that it is THEY who must adapt to the culture, not the culture adapt to them. If they don't adapt, then it will be a frustrating experience and eventually they'll leave. If one does adapt, it can be a super interesting and rewarding experience. According to the US State Dept, only 36% of Americans own passports and interestingly, the most US passports issued in a year was leading up to the Obama / Romney election. Next biggest, last year:



Volcano-wise... I'll take them and earthquakes any day over hurricanes and tornados and the violent storms you've got more central to the battle between hot and cold. Our weather is really pretty mild in comparison. Being in a geothermal active area means we're always releasing pressure and so it is very rare to have violent (relatively speaking) eruptions like the Mount St. Helens back in 2008. We've got over 200 volcanoes in our little country and 10 of them are considered active.




I live between the 2nd and 3rd in the video (Rincón de la Vieja & Miravalles) where they are showing the 10 active volcanos and the last 2 are the ones Jeff showed in his backyard pic. So we've got 1 volcano for every 22,500 people. Not a bad ratio!

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Sam

It is pretty hard to complain when every day is between the mid 70s and 80s.

I've been monitoring my fish tank while I prepare for adding fish and it seems to be fairly stable at around 72 degrees.

+1 Sam, re living overseas. You definitely have to adapt and grow with each different culture. I think we are both lucky in that we have family here. Certainly makes a big difference in how you experience everything.

Couple of questions today for iAVs-ers.

1. Recognizing that my "sand" is more coarse than suggested, with sand that is within the proper range for size (1-2 mm), how long does it typically take for the water to make it all the way down the furrows? Let's say for furrows that are about 3m or 10 feet. Would you expect it to happen after the first couple of floods or does a slight biofilm layer need to build up first?

2. Could an iAVs bed act as a solids and fines biofilter for a DWC system? I have been wondering if you could simply have an iAVs bed with perhaps a few plants, but definitely not enough to take up all the nutrients. Could the water then flow to a DWC bed for growing other crops? It seems like the iAVs bed does essentially what many DWC filter systems do. Would the sand hold back essential nutrients for the DWC section or would the water from the iAVs growbed contain enough?

It's been a week now with my pump running every two hours for 30 minutes. The system is still fish-less as I'm trying to clear the remainder of some silt in the water by running it through the sand bed. No sign of algae on the surface of the bed - I'm hoping that once a small biofilm builds up that the furrows will flood more evenly. Currently, the water makes it almost 3/4 of the way down the furrows.

Forgive me for not reading up better on this before asking silly questions about iAV, but what about starting with a little bit of a slope for better water distribution and then if it becomes too much as the system matures, pile a it a bit deeper?

How's that overhang you've got with the laminas working? It looks nice. Was that roofing purchased at EPA? Did you notice if it had UV protection or anything like that? I've got to find better than what I've used in the past...

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Sam

Hi Sam,

The thinking behind not sloping the iAVs sand bed too much is that if you have to do that, then the water is likely draining through the media too quickly to be effectively filtered. Now, clearly that is what is happening in my system since the water is not making it all the way down the furrows... yet. Mark McMurtry (the originator of iAVs), on AN told me that his sand beds flooded fully from the beginning. So, despite the fact that after some biofilm has built up and the furrows (perhaps) flood completely, I'm left wondering how effective my media will be filtering. I'll, of course, be able to test that once I have some fish!

The laminas are from EPA, yes. No idea about UV protection but I'm hopeful they have some since they -should- be designed for external use.

Cheers,
Jeff

Some updates! I finally added some fish to my system - 20 Mojarra (I think Cryptoheros septemfasciatus) - a common river fish in Costa Rica that is hardy and easy to keep. The pH reading in my tank surprised me (I hadn't tested it for a while) - up around 8. I guess the my sand isn't as inert as I was hoping. However, the fish seem to be doing okay so far. I also added a common pleco (Hypostomus plecostomus) for algae control. And I've added some plants to my grow bed. A combination of cilantro, some sweet peppers, and some very sad tomato plants that I had been neglecting. It will be interesting to see if they can recover in the sand bed! Maybe I'll add a healthier one today as well for comparison. For added fun, I planted some seeds directly as well to see how they do.

I'm also experimenting with microgreens again. I starting with microgreens when we lived in the Boston area and really enjoyed growing them (mostly arugula, kale, bok choy, and sunflowers - which are amazing, btw). My idea is to explore the market for selling a combination of microgreens and "organic" vegetables direct to families here in the Central Valley. So far the biggest hurdle is figuring out how to get bulk seeds since growing microgreens requires significant quantities. Not so difficult for common things like lettuce and tomatoes but apparently not easy for other species. The importing of seeds to Costa Rica, from what I've gathered so far, is not a simple process. Even seed suppliers here don't seem to have much variety.

Added some more plants and a few different seeds to see what will happen. The seeds are lettuce, chili pepper, spinach, carrots, pak choi, and cucumber.

Jeff,

Nice update!

So your culantro was transplanted from somewhere else? I've always just grown from seed, but will be watching with great interest to see how it does. As we approach the dry season, I'm sure we're not too far off from having a hard time finding decent culantro in the grocery stores...

It looks like you've got the furrows figured out, or they matured as you suspected and are now working as planned.

Where did you get those Mojarras? Can you post a few pics when you have a chance? As I'm sure you know, Ticos can be fast and loose with names and I've heard Mojarra used to describe everything from bait fish you find in the shallow coastal waters to Tilapia. I've never seen those cichlid's in acuarios, but we've got VERY few even worth visiting up around me. They look like little Tilapia...

I'm building a new office right now which has slowed me down a little on my Aquaponics project, but I keep refining plans and hopefully before this dry season is over I'll have fish in the water.

Looking good up there in the GAM!

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Sam

Hi Sam,

Yeah, the cilantro was a "cheater" plant from the garden. The bigger tomatoes as well. The smaller, sad tomatoes were in a couple of buckets. None were in very good soil so I'm hoping that the iAVS bed, such that it is, will make them happy.

The water still only flows 3/4 of the way down the furrows so my sand is just too coarse. I'm also thinking it is slowly increasing the pH of my rainwater since it's now around 8. The source rainwater was 6 something. Anyway, hoping to start something larger and more "designed" on the new property over near San Raphael de Heredia. Need to get some walls and electricity first though.

I'll try and take a couple of pics tomorrow of the fish. I found them at Acuario Amazona in Santo Domingo. Nice little shop - sometimes has Tilapia, although his supplier seems unreliable. Likely not a big seller for aquariums.

I'm emailing someone from http://semillascr.com/ about importing seeds. They are apparently an "official" importer (i.e. use the correct forms, etc) which means it ain't cheap but I think they can order directly from JohnnySeeds. That would be pretty awesome if the economics work out. I'll let you know what I find out.

If we had another car, I'd offer to drive up and help out with your new office. Or at least bring some beer! Some day...

Howdy Jeff. Did you do the vinegar test on the sand? That'll tell you something about the presence of lime, if it bubbles or not.
I did the same thing transplanting from the dirt garden to my AP. Some stuff did very well one time and not the next. I got transplanted cucumbers from the garden before it froze last year and they flowered and made new cucumbers plus ripened the ones which were on the vines! This year I can't seem to get anything, but tomatoes and peppers to grow. Go figure. I'm going to try Kale and celery here in a bit, but like Sam, I've got my hands full with a construction project. I need a younger me to help out, or just do everything so I can sit back and relax, hehehaha