Minor Surgery, Swirl Filter and PH Woes, Nifty Screens

My swirl filter turned out to be a partial success. That also means it was a partial failure. The problem was with the drain pipes from the tank to the swirl filter. These pipes were a "left-over" arrangement from when I had my system set up with the grow beds emptying into the fish tank. The water returned through these 1" pipes into the tank.

With the CHOP system, these pipes were to act as overflow drains so that the tank water could fall into the swirl filter and then into the sump. The problem is that I had too many 1" pipes too close together, and there was not enough concrete between some of them, resulting in some serious leakage. When they acted as drains from the grow beds, there wasn't a problem since the water in the tank was never close enough to the pipes for there to be water leaking between them.

The only way I could think of to fix this problem was by removing the pipes completely by knocking the tank wall down to the pipe level, replacing them with one 3" pipe, and re-pouring the concrete tank wall. Then I'd need to wait at least a week for the concrete to cure enough before applying tank sealant, which itself will require another 3 days to fully seal.

Of course, this would mean draining the tank and coming up with a makeshift tank and aquaponics arrangement in the meantime. I removed the blue barrels that were acting as sumps and replaced them with my third cattle water reservoir container. This is now in place and receives the grow bed water. So, we're back to the original type of arrangement while I wait for the concrete to cure.

Current Tank - Grow Beds Drain Into Tank. Former Concrete Tank Undergoing "Surgery"

New 3" Overflow Pipe and Repaired Tank Wall

Swirl Filter

The swirl filter worked pretty well. I used a discarded washing machine drum and fitted a pipe down the middle. The pipes from the tank (the 1"-ers) I connected to large 3-inch pipes that went vertically downwards into the tank. These I drilled plenty of holes into the bottom so that all the tank water falling into the swirl filter would be coming from the bottom of the tank, where most of the particles are. The over flow pipes were connected to elbows and extended so that when they drained into the swirl filter, they entered the filter all the way at the bottom. This would force the water in the tank to travel from the bottom all the way to the top, and allowing for the maximum distance possible for particles to drop out of the water before the water drains through the stand pipe.

Washing Machine Drum Acted as Swirl Filter. Sorry I didn't Get a Picture of it When Fully Set Up

Although it only ran for a day and a half before I had to shut everything down due to the leakage problems, it collected quite a layer of particles in the bottom. Unfortunately, these washing machine drums are not made with the same fittings as PVC so in addition to my tank leakage problems, there were also leaks in the swirl filter.

In my next version, I'll just use a portion of a blue barrel. The principle works quite well, which is all that matters. The washing machine drum will have to find another use.

PH Woes

In the meantime, PH levels continue to be high (8.2-8.4). This is after changing the gravel with gravel I had already tested to ensure it would not raise the PH. I can also rule out the concrete in the tank since for the last week no water has been in contact with any concrete. I've gone from trying to lower it with lemon juice to using phosphoric acid. Every time I lower it (to say 6.8-7.2), it just climbs right back up to the 8.2-8.4 range in a day or so. I've also changed a good portion of my tank water (on several occasions when my nitrates were too high) with water from the spring which has a PH of 6.4-6.6.

I have to say I am completely befuddled. For now, I will continue to lower it by adding a little phosphoric acid every day. If there is something in the water that is buffering the PH, it will eventually be neutralized by the phosphoric acid and then I can keep it at a lower PH. That is the hope, anyway.

Removable Greenhouse Shades

Since I've had extra time while waiting for the tank to cure and so forth, I decided to install some greenhouse shades.

My greenhouse consists of a double-pitched roof, with one side pitched about 3 feet higher than the other so that there is a natural exhaust vent for hot air to escape through. The roof is transparent polycarbonate roofing sheets and the sides are wrapped in anti-aphid screening.

When I first installed the roof, I thought it would be a good idea to also seal the roof on the inside with anti-aphid screening, since there are gaps and cracks in any roof that may allow bugs in (even though it may be water-tight perfect).

It turns out that is not such a good idea. The screening material is white, and when installed horizontally, it makes the inside of the greenhouse painfully bright - to the point you do not want to be in there.

I decided to remove this material, and also looked into installing some shade material over the plants. After researching typical greenhouse shade material by talking with a local provider, they told me the most I want to shade is by 50%. Shading material comes in different "densities" allowing you to block anywhere from 50% up to 99% of sunlight, and what you use depends on what you're trying to grow. Leafy vegetables, tomatoes, and just about everything else I have need lots of sunlight, so there is almost no reason to shade at all. However, I wanted to be able to put something up, if only for when working inside the greenhouse.

I devised a removable shade clamped on PVC pipe and hung on wires. So far, it works pretty well. I can make the shade open or shut by pulling on one of two sets of ropes. It works just like a horizontal curtain. It took a while to figure out all the "bugs", but now that I have one quadrant of the greenhouse done, it won't be too difficult to do the others.

I also decided my fish needed some shade. They are supposed to prefer dark spaces, plus all the sunshine promotes algae growth. This makeshift shade will do for now:

Moving the fish to the temporary tank I assume was pretty stressful on them. Unfortunately, one of the bigger fish died. So far, it looks to be a one-off incident as none of the others have died and that was three days ago. The good news is the fingerlings are doing quite well. I know you are supposed to separate them from the grown fish, but so far they do not appear to be being eaten. Here you can see three different sizes of fish:

The "Everything-Got-Changed" Video

Well, we managed to do all sorts of work this weekend:

• Took down the large grow bed, cut the table legs down, and refilled it with new gravel.
• Installed a second large grow bed and changed the gravel in the bath tub grow bed.
• Dug a hole for our sump tanks. These are two interconnected "blue" barrels.
• Built a steel, lockable lid for the valuable equipment area.
• Built a swirl filter and stand.
• Reconfigured the pump to function out of the sump, from where it fills the tank and the grow beds, in a "CHOP Mark 2" setup.

In all, too much to write about, so I made a video:

The PH will probably take some time to come down. It hasn't yet. I've added lemons and will add a few a day until it does. And if this gravel turns out to also be bad, I just might put myself in the sump tank and bury myself in it! I tested it first, so this unusual AP maneuver should not be necessary.

I'll fix the problem with the overflow system next week. I'm also glad I can now route the drain pipes around the outside of the grow beds. I can walk up and down and across the greenhouse and between beds without worrying about pipes.

Cha - Cha - Cha - Change is gonna come....

Got out to the farm and AP set up Thursday. Earlier in the week, I tested gravel samples from four different quarries for their effects on PH. I just put some gravel in a small container and added tap water. I tested the PH of the tap water before adding it to the rocks, and a few hours after adding it. All samples caused the PH to rise. This could be do to residues left on the rocks and may not necessarily mean they actually contain limestone. In order to determine whether the PH effect was due to residues or to the rocks themselves, I brought the PH in all samples down to 6.0 by squeezing a little lemon in each container. Then I waited a day t see what happened. Two of the samples held at 6.0 and the other two rose back to above 8.0. Counting the gravel I'd already used in the system, that means 2 out of 5 quarries produce rocks that won't raise my PH.

Unfortunately, this means I have to haul gravel from the city all the way out to the farm, in my truck. I took 300 kilos out yesterday and am sending a truck with the rest tomorrow.

The plants are doing remarkably well considering they're living in the PH equivalent of Mars. Alright, I know they don't look good, but I am just surprised they are standing at all. The squash (lower right) has about doubled since Sunday. The other have grown a bit, though I haven't taken actual measurements.

The plants in this bed aren't doing as well. They are the ones that suffered through the siphon-failure last week. In any case, I'm happy they're even standing!

Since I have to change my gravel anyway, I've also decided to make a major, but I think worthwhile change to the system. Right now, my beds are higher than my tank, and they drain into the tank. This is OK, but the beds are pretty high up. The tables they sit on are 70cm high, and the top of the beds are another 40 cm high. That's well above my waist and will make picking tomatoes or cucumbers later a bit of a chore. You can probably appreciate the height issue in this picture I posted earlier.

What I'm going to do is cut the legs of my beds down so the beds are 40cm off the ground. I am then going to sink a barrel into the ground near the fish tank and drain the beds into there. I will move my fish tank pump into this sump and use it to pump water into the tank and into the grow beds. The tank will be fitted with an overflow tube that drains into the sump. This system has been tested and featured by Murray Hallam out of Australia. It's called "CHOP", for Constant Height, One Pump. The "constant height" refers to the fish tank water remaining at a constant height, as it overflows into the sump, and no longer raises and falls with the filling and draining of the grow beds.

Yesterday, we cut one of the tables down, put a new grow bed on top, and filled it with new gravel. Unfortunately, the 300 kilos of gravel were not enough to fill the bed, so I could not get it hooked up to the system yet (or transplant my plants to it).

Tomorrow, I'm getting 900 kilos more delivered and will fill the rest of this bed, one more large black bed, and the bath tub. I also plan on getting the barrel sunk and the pump placed in it so the system is fully working in the new configuration. Will post lots of picks with the new set up after it's all done, if I'm still standing!

Almost forgot: One of my fish has delivered dozens (maybe 100?) of fish tadpoles! I knew this would happen eventually, but was very pleased and excited to see it happen. Maybe I won't need to buy any more fish. Will try t get some pics taken, but they are so tiny, I don't know if they'll show up.

Tropical Storm Thomas and Other Adversaries

I was not able to get to the farm until Saturday (I normally go Friday). Tropical Storm Thomas wreaked havoc across Costa Rica, knocking out bridges, roads, water and electricity all over the place. One community suffered a massive landslide that killed over 20 people. In another, 50 homes were destroyed by a wall of mud (fortunately, people had already evacuated).

By Saturday, there was one route open to the farm. The storm had passed and clean-up was underway everywhere. The road was dirty, but passable. Here's a pic of one portion of the road, mostly cleaned up after a small landslide:

(Between Puriscal and San Pablo)

Upon entering the greenhouse, I immediately noticed something was wrong. My bath-tub grow-bed was just fine: the plants had grown some, and despite looking a little pale (due to nutrient block-out caused by high PH), they were upright. In the other grow-bed, the plants were severely wilted - some completely lying down on the gravel.

Bath-tub grow bed - plants are fine

Other grow bed - major trouble!

What had happened was the siphon failed. It only failed for a few hours, but in this climate, that was enough for the sun to heat up the bed and gravel. The bed and gravel were warm to the touch. The good news is the siphon didn't fail on its own. Carlitos had shut the pressure-release valve that allows some pump water to spray out upon the surface of the tank. Without this valve set correctly, inflow into that bed is too high for the siphon to auto-shut-off.

Also, I noticed the drain pipe from the grow-bed to the fish tank was sagging big-time in one point, essentially making it so water would have to go uphill. The pipe was fine last week, but with the heat and the weight of water going through it for a week, it sagged. I fixed this with some blocks and got the siphon going again.

After just a little more than an hour, the plants had begun to resuscitate, which I found remarkable.

Last week, I wrote about my PH problem. I decided to drive down to the nearest river in order to extract and test some river stones. I put these in a plastic bin filled with water Saturday.

On Sunday, I tested this water and the PH was again high! I couldn't believe it! It wasn't as high as my gravel water, but it was still higher than what the water that was added to the stones was.

Suspecting that this may be due to residual sand left on the rocks, I decided to add a lemon to the mixture. This immediately brought the PH down to 6.0-6.2. Four hours later, and that PH is still holding, so I think whatever caused the PH to rise initially is either not something in the rocks themselves, or if it is, it's not something the rocks will release more of when the PH drops. I brought the bin and PH test portion of my water testing kit back to the city with me and will test throughout the rest of the week.

If the river stones prove useable, I will next have to devise a way to get down to the river with a rock-sifting arrangement and load the truck up.

In other news, the fish look good despite nitrates at between 20-40ppm. PH continues to be through the roof. Quite frankly, I'm impressed with how good the plants look despite the high PH. Ammonia continues to be about 0.25ppm. Carlitos has also been measuring ammonia daily, and it's yet to have gone above 0.25ppm. This could be due to the large size of my fish tank, and small quantity of fish. I'll keep things just as they are until I can replace my gravel.

PH, high PH, Ammonia, Nitrate

And here's a better picture of the set-up as it now stands. There will eventually be at least 2 more of the large black grow beds. The fish tank is in the back left corner.

Basic Components: water pump and air pump.

My "Basic Components" compedium was left in the dust for a while and it's time to bring it up to speed.

I'd written about my main fish tank pump before. It's a Little Giant brand pump, and here are the specs for anyone that's interested. It works in-line, or submerged. I have mine submerged. So far, it's worked great, and it's easy to clean. I assume pump technology is pretty well advanced, and have faith this thing will perform for a long time. However, I am planning on getting a second pump ASAP, just to have on the shelf in case I need it. These are mechanical devices after all, and if there is one thing I've learned over the years, it's that if something can go wrong, it eventually will - usually when it's least convenient!

My air pump I had to get on line. The local aquarium market is aimed a small household fish tanks, probably for people with a few gold fish and such, which I consider extremely boring and a waste of time and money. I mean, if you can't eat it, and it's not a dog, what's the point?

In any case, I tracked down a nice air pump online. This delivers 16L of air per minute, through eight outlets:


The air tubing is sold separately, as are the air-stones. Right now I only have four air-stones hooked up (because I didn't buy enough tubing), but that should be way more than enough air for the amount of fish and water I have.

I'll be posting the specs and set-up for my battery-back-up pump system hopefully this weekend. After that, I hope to get some plant and fish action soon, or there will not be much to write about for a few weeks!

Think Twice Before Feeding Your Fish Chicken Shit, and Other Mysteries.

Today I had the rare opportunity to visit the farm and my AP system during the week. I had to pick up Tora, a Malinois half-breed 10-month "pup", and bring her into town to get her fixed.

As I posted last week, I was surprised to find my nitrate levels were through the roof. I was initially very pleased to see this, until I began to really think about why this shouldn't be possible. Also, a full 30% of my readers (Ready), commented about how this was likely due to something other than the presence of nitrogen fixing bacteria. He suggested the chicken waste, which in an earlier post I had indicated was likely to be in my gravel, was the likely culprit. If so, and if more chicken waste was being somehow added to the system, this could pose a serious problem.

Well, as it turns out, someone (me) had suggested to my caretaker, Carlitos, that Tilapia were such hardy fish they could eat anything, even chicken shit. Well, sure enough, Carlitos took me up on my suggestion and was feeding them a few pellets per day (four to be exact). Mystery solved!

Now, even with this gross introduction of nitrate to the system, nitrate levels were down today compared to last Saturday and Sunday. When I added the extra bed, I also added more water to the system, so that obviously helped. The good news is that nitrite levels are now detectable, as seen in this nitrite and nitrate test:

Those nitrite levels were not detectable in my weekend test. So, some bacteria has apparently started to make itself evident.

Other than chicken-poop, we were feeding the fish dead bugs and dog-food pellets. The dog food pellets did not prove very popular, but they did eat them, grudgingly. Both of these ideas were spawned by my desire to avoid buying fish food, and by wishful thinking that I'd get my own fish-food supply system going soon (duckweed or worms). Well, today's realization and experiences led me to go straight to the agro supply store and pick up real fish food:

That's 14 kilos for about $22. Enough to feed my existing fish for a very very long time. Of course, I'll be adding more fish very soon. The fish loved the pellets. Of course, after a week of dog food and chicken shit, who wouldn't?

My other "mystery" revolves around my PH levels. The water I used to fill my tank comes from a natural spring. Its PH is around 7.0-7.2. The water in my system, for whatever reason, is at PH 8.0. JAG suggested I check my gravel. I did so by filling a small container with natural-spring water and checking the PH before and after adding gravel. After letting the gravel sit in the water since Sunday to today, the PH is at 8.0, so sure enough, it's the gravel.

I am not quite sure what to do about this at this point. Changing the gravel is a huge proposition and I am hopeful I can get the PH down over time. Maybe hope is not a good strategy. I have read of systems going from 8.0 down into the preferred 6-7 range over time, but I do not know if their high PH situation was caused by gravel or something else.

For now, I am content to wait, watch, and see how the plants behave. The ones I planted in the bath-tub appear OK. One, a jalapeno plant, I took out of a planter because it looked like it was drying out and getting ready to die. Since being in the AP system, it has recovered significantly.

The Jalapeno plant is the big one on the left. Everything else is basil (mostly), one cantaloupe, and there are two asparagus crown I took out of my dirt garden and am testing here.

I went to the nursery last night, picked up plants for the other bed, and planted them today:

That's Carlitos in the background. Here's a close-up of the plants:

I installed these laundry baskets in the tank today in preparation for hopefully getting more fingerlings this weekend. They're meant to provide shelter for fingerlings - a place the can be away from the big fish. I don't know if this is really necessary or not, but it seems like a good idea I got off Murray Hallam's site.

And here is Tora, who made today's progress possible: