Backyard Aquaponics
A place to discuss aquaponics

Just a quick note pond-

If you run into this situation again, drop the pH. Ammonia toxicity is closely related to pH and temperature. At a lower pH, unionized ammonia becomes less toxic even to a point of being non toxic. Other fish are more sensitive to pH swings but tilapia won't care.

So... Lower pH, wait for bacteria to consume/convert ammonia, then slowly let it rise back to your desired level.

Dr Rakocy had ammonia levels over 50ppm at one time with fully stocked tanks... But a low pH kept them all alive

Thanks Ryan, that blows my theory on ammonia toxicity in my case because my PH was already very low at 6.2-6.4 at the time. So I need to look into other causes of death. I'm starting to realize I'm very lucky to have low PH assuming its natural and not something left behind from an IBC container.

Since my last post I made some changes to the bottom drain and allowed the ammonia levels to drop down to 2ppm. Yesterday I tested with a single small goldfish the size of a small tilapia fry. He lasted about 8 hours in the FT before disappearing through the bottom drain. Today we are taking the DWC rafts out to hopefully find him.

Is there such thing as too much flow to the FT? Assuming my drains etc can handle it I'm running about 1200gph (5200 liters per hour) into a single 1000 LT FT. This means I'm replacing my FT water 5 times per hour. I know the recommended (low end) is only once per hour. So maybe my problem is I've created a roaring river they just can't tolerate? If so this could be as simple as a T to allow some water back into the sump.

Meanwhile I need to go back to what Ron mentioned about a basket or liner or modified drain cover until the babies are at least 2 inches. I need to make either a false bottom, a net basket, limestone free rocks around the drain. Our current method is using a 4" net basket from our DWC that has some extra holes and cuts in it. It would be very simple for me to use rocks I already have them and have already tested them with vinegar.

This is still not going well, but at least its 1 fish at a time. Its also a lot easier to find a goldfish then a tilapia when we are observing this kind of escape artist behavior. I hope to find this fish alive at least.

if your drain has grating big enough for the fish to swim through they are going to swim through it weather you have high flow, low flow or no flow. The flow is not the problem if your fish can swim out of your fish tank.


because of big piping in large tanks this is why i typically have separate fry tanks


I dont think your flow is too high or intolerable. some fish may actually like always swimming against a current and may be happier/healthier for it... maybe not goldfish but again the word you used was intolerable and i dont think that is the case at all. The main negative is just the extra energy it takes to turn over a fish tank 4 times over one which may be a trivial negative to you

Thanks Brain C.,
I need to fix the grate before I try anything else to test the fish health. I have drained the FT to have dry access to the drain now and this time my effort will be more long term. I expect it will look like a small PVC cube with mesh screen around it???

I'm going to dig around for ideas here today on how other people have done it. I will post what I find along the way.

Hi Pond sucker, congrats on your great thread.
Im a newbee here and this is post no1.
Your getting-fry-sucked-in problem sounds like the kind of thing a pool shop deals with every day.
Mind you it could be quite a dive if ones outlet was down the bottom of the FT!

Three rings of poly pipe, or garden hose (joined with a dowel or similar) and tied with zip ties to form a sphere would hold a net bag open for those little fellers I recon. just make sure you dont loose the whole shebang to the bottom of the tank. And make sure they can still get some food if you are feeding them.

I had success with a milk crate with shade cloth around it, that was weighed down and surrounded a bottom drain. I found anything around pvc clogged up, and I could turn drain off, pull out milk crate, hose off solids once a month, in comparison to checking a pipe daily.

Great thread btw and keep on trucking!


Sent from my iPhone using Tapatalk

Bcasey,

Wouldn't that make the covered milk crate the primary solids filter? Did you have any nutrient deficiencies because of this, that you could tell?

I just used it until fish were big enough, so for about a month, too not fit thru traditional pipe work. As it was early on in the cycle, didn't notice any deficiencies other then what I expected.


Sent from my iPhone using Tapatalk

Pond sucker, any updates?


Sent from my iPhone using Tapatalk

Yeah Pond you sort of disappeared on us.

still no updates? Are you okay buddy?

Pond....where are you???

First I'm alive and well, and I will do my best not to allow real life things like jobs, responsibilities or bathing myself ever again get in the way of aquaponics and I hope you all accept my apology for disappearing like that.

It has been 2 days short of a year since my last post. We had to put our AP project on hold for a large part of the last year due to a series of life stuff and work projects. We did finally manage to get past the last hurdles of AP challenges.

As of my last post we had attempted to add fish and were experiencing problems with the filter on the FT drain failing to block smaller fish from passing from the FT into the filter barrels. We also had a second problem with low PH that just always stayed between 6.2-6.4 without any buffering, at the time. We had killed about 50 tilapia and 2 goldfish testing our drain cover and possibly PH shock at the same time.

So over the past year, I did three things with the AP system without going to the point of adding fish and without really spending much serious time or effort on it. For that I will do 50 Hail Marys, some pushups and take a lap after I submit this post....

1) The little work I did with AP was mostly focused on the PH over the past year. When it rained, I checked for changes. When it rained so much that ground water potentially entered my sump I checked again. We measured each bed, dwc, sump and FT individually, hoping to find an area affected by some other "nasties" that were changing the acidity. I have even checked the PH of every faucet in my home (all, but the kitchen sink test at 7.4....kitchen sink is 7.9? do I need a new faucet?) I bought a second digital ph tester and have had the water verified at my local fish store to make sure I'm not having equipment failure. Originally I had hoped to see my system PH magically correct it's self. It never changed more then .2 and always went back to about 6.4 so finally I decided to start buffering. I purchased a few things... Potassium Hydroxide PH 12-14, Hydrated Lime PH12.4, and while ordering I picked up some calcium chloride as well though it is not intended for buffering PH. And I ordered what I perceived to be a high quality feed so that it would be ready once I felt the buffering was successful.

Buffering notes - I believe my total water volume is about 2700 liters since I am not counting any grow beds as they can all be empty simultaneously for brief moments due to the indexing valve. I started slowly with a single spoonful of hydrated lime applied at the sump tank and watched for changes over the next 48 hours. Eventually I learned it takes about 3 spoons full every 14 days to maintain about 6.8PH... I also started using the potassium hydroxide on every 3rd dose instead of hydrated lime per a video from Dr. Nate though I have seen everyone has different methods for this process. At one point during my testing I raised the PH to 7.4 just to time it back down to 6.8 again. Finally I felt comfortable enough that I can control and monitor this before killing any more fish. If anyone is trying to learn from this, it should never take a year to do this part, I was focused on other projects in life. You could probably sort this out over 2-3 weeks just give it 48 hours to stir around your system before you add more. If you have fish maybe smaller size doses more often, without fish you can test with larger doses.

2) Because we were showing nitrates and low PH I wanted to add plants early to the system while I worked on the two main problems so I populated the DWC with things that just grow with little effort such as basil oregano kale and smaller verities of tomatoes. I also tried several types of beans and peas, cantaloupe, and lettuce. To my surprise, without any fish at all, some are still alive though not very healthy. And the beans and peas especially seemed to fail. As the PH was buffered I did notice changes in the health of the plants, specifically the purple basil turned darker days after the PH was buffered. We did have a single cantaloupe fruit that grew to adult size in the DWC.

3) We solved the problem with the fish passing from the FT to the filter barrels with a layer of rocks. So early this month I caught a few fish from the stream behind our house and tossed them into the tank to see how they managed. After watching them for 3 days everything appears good and I've decided to add fish. Our solution to the fish passing from FT to filter barrels with rocks may have a side effect of creating blockage for my solids... time will tell now that we have added fish.

So on 8/12/2016 we added 50 tilapia.

They have enjoyed their new home for almost two days now and I'm almost afraid to announce it yet but .... I think we have fish? I should go look again before I hit send... yup, we have fish!

Here is a video from earlier today with a lightning storm in the background too, I had to call ahead for that part!

Tiffany just tested the FT with the API kit
ph 6.4
ammonia 0.25 ppm
nitrite 0ppm
nitrate 0ppm

I expect to see the ph continue to drop eventually all the way to 6.2 just because that is how our system tends to move. Now that there are fish I plan to buffer much smaller quantity more frequently. My best effort to convert 3 tablespoons / 2 weeks came out to .64 teaspoon/day. So for now I'm going to use a 1/2 teaspoon size dose of hydrated lime/day as my buffer And I would like to see it at around 6.6 before stopping only because I know it will drift back down when I stop for a day if it gets that high at my current rate.

As for ammonia the volume and flow rates are very high on my system if it ever gets near 1.0ppm I will remove a fish for consumption either for myself or to go live in the turtle tank where we have a slider turtle with her own 680 liter setup and some feeder minnows. So far the ammonia hasn't had time to have a problem though I'm aware I have repeated my mistake of starting with a large stocking density for my FT, at 50 quantity. I have a little bit better plan for how to handle that if the time comes.

Nitrite and nitrate I believe are already being consumed by the plants in the DWC mostly basil plant that has a tree trunk, I still don't understand how the basil grew over the fence before the fish?

Feeding plans... at this size I'm looking at charts that are telling me I need about 35 grams/day by weight, I have no idea if this is enough or too little. Also I'm feeding "classic trout" to small tilapia, basically higher protein then what they need. I will increase it or decrease it based on what I see with ammonia levels and water clarity going forward. 35 grams seems like too much though, check out the photo we actually used about 1/3rd of that.

We need to go through the seed collection for winter months and start seeding. I am about to clean out the failed plants that I left in the system to show on the video above what happened without fish.

I am so happy your'e back. I thought maybe you got drafted.