modified lung

No heater necessary. Definitely keep them below 80°F or they'll slow reproduction. I've never used a filter with them. I like greenwater and spirulina powder but yeast works too. Give only very small amounts of any dry feed. They eat more in low light so crashes are less likely if fed in low light. The smaller the tank the easier they crash regardless of water quality. 5 gallons works fine. The best Daphnia culture I ever had was in a shallow outdoor tank of rain water with cow manure. It grew very dense and stayed that way for over 3 months with no intervention besides harvesting.

I do this with a 55 gal barrel in my backyard but with no heater or air stone and Simocephalus instead of Daphnia.

The blackworms have been living outdoors in a bucket in one of my 300 gal tanks. A tiny 1 watt pump in a floating filter sock pumps water into the bucket which flows out a screened hole drilled in the front. I've been placing water lettuce in the bucket with the lid mostly closed so the worms have at least a small constant source of food for when i forget to give them more vegetables. They seem to like it. I did have another die off ...sort of. I hooked an extra, more powerful air pump to my solar controller to run a protein skimmer which took far more power than expected. The extra load drained the battery bank over night right before the first overcast day of the year and the five more that followed. The bucket was quite packed with blackworms (sorry no new pictures since the last one in October) and I'm guessing oxygen went very low. It looks like most of the worms crawled out of the bucket and into the main tank where the eager ricefish were waiting. Oops. But why fight your own incompetence when you can embrace it? That's what I always say. I cut a small solar panel off and old solar air pump that kept jamming and connected it to the 1 watt water pump. If the pump only runs during the day, when the population of blackworms gets too high, they'll leave the bucket in the late afternoon and become a snack for the ricefish. A periodic auto blackworm dispenser. Maybe that will work out. The blackworms hanging onto the water lettuce will still likely get enough oxygen and ensure there are always some in the bucket to repopulate. I thought the tower was empty but upon dumping half of it into a container I saw hundreds of very short, recently segmented blackworms were still in there. Repopulate they shall ...again. @Beardedbillygoat1975

Hmm, it shows up on my end. They're both gifs.

Rosey Loach feeding frenzy

***Freshwater Microalgae (5): "Mixed" vs "Pure" Greenwater (2)*** I repeated the same test in two separate sets of jars. 15 adult Moina were added to each jar and allowed to grow for six days. Trial #1 Trial #2 The results in each trail were basically the same: Jar 1: Tetradesmus The lowest population growth. Adults in trial #1 grew to medium size and in trial #2 to a small size. Jar 2: Scenedesmus Second best population growth. Adults grew to a medium size. Jar 3: Chlorella (in recycled moina water) Less population growth than jar 2 but adults grew to be larger. Jar 4: "wild" By far the most population growth and the largest sized adults. Trial #1 was exposed to a good amount of light during the days. Trial #2 was in lower light which is probably why the microalgae in jar 1 and 2 settled much more. It's odd though that jar 4 in trial #2 didn't have any settling. Maybe the Moina population grew fast enough to eat all the microalgae before it settled? These trials still have the same problems as before which makes the results not as concrete as I'd like. But wait ...there's something else that does point more toward mixed greenwater being better. Oops ...Accidental Trial #3 ...sort of I also had a 2 gallon jug of recycled Moina water growing Chlorella. I accidentally dropped a few Moina in the jug the same day I set up the other jars. Oh well, I decided to roll with it. I dumped a quart of the jug and refilled with water from the Tetradesmus and Scenedesmus cultures. We now have a mixed culture made from jar 1, 2, and 3. I actually forgot I dropped the Moina into this jug and a day or two after I added some low P fertilizer to darken up the culture. The culture definitely darkened and also this happened: The culture tested with 0 ppm NH3/4+ and 0.25 ppm PO4-. We can compare this to jar 3 in the other trials which only had Chlorella, 0 ppm NH3/4+, and 3.0 ppm PO4-. Except we know the greenwater in this jug was recently fed whereas I don't know how long jar 3 sat without any ammonia to eat on—meaning the greenwater in the jug was likely much more nutritious than in jar 3. If similar results happened just by mixing the three cultures without adding the fertilizer (oops), I think we could say mixed green water is better. Instead right now I have some Moina in a jug of recently fed, dark, healthy Tetradesmus. We'll see if the Moina population explodes just as fast. Then in the next experiment I should have some pure and mixed cultures properly fed up. If the mixed culture wins again, then I think we can say for sure whether or not the lazy "wild greenwater" way is the better way. Who am I kidding? The lazy way is better no matter what.

@nabokovfan87 now my gears are turning.

Looks like a female cyclopoida, a type of copepod. The two little circles on it's back are egg sacks. They're good food for fish but they can eat baby Daphnia and rotifers so they can be a pest in live feed cultures.

There are a number of microorganisms and a few plants that eat carbonates and bicarbonates. That would be my guess.

It's amazing how little info is out there about growing good freshwater greenwater cultures at home. I see people claiming success with various brands of guillard's f/2 media but that stuff was really made for marine phytoplankton. I tried it for a while and freshwater microalgae seemed to take off fast but crash faster. The original recipe assumes seawater is being used so it doesn't have any potassium, calcium, or magnesium included. Idk if any of the brands modify it at all. Amano shrimp? I haven't tried outdoor breeding. Do they have a wide temperature tolerance? I tried it indoors a few years ago. The babies died on the second week after the first water change.

***Freshwater Microalgae (4): Nutrients I've been a little obsessed with greenwater again lately. Look at these two cultures: Both were started on a week before this photo with only one difference. To the culture on the left I added an NPK fertilizer with a P and K level 25% lower than N. To the culture on the right I added an NPK fertilizer with a P and K level 25% higher than N. As you can see the low PK fertilizer did much better. First lesson: use a low P fertilizer; greenwater does not like too much phosphate. Getting a Darker Culture Here's the same culture two weeks later: They didn't change much. If not for the 10 ramshorn snails in each tank, both of these cultures would probably have died out. But, although the snails sustained the cultures, they were not enough to grow the cultures. After the last photos, I added more low P fertilizer but this time to both cultures. Up until yesterday, another week later, the cultures still didn't change much. But here's a photo taken today: Wow. The tank on the left, I want to say twice as dark. Tank on the right, murdered dead. What happened? Yesterday I added a cap full of Seachem Replenish and a few drops of Vitachem to both tanks. The original low PK cultures loved it. The high PK tank, not so much. Water Testing Time Before adding the second fertilizer, lefty showed 0 ppm NH3/4+ and 0 ppm phosphate on the API liquid kits. Today lefty tested 0.25 ppm and 0 ppm. Before the second fert, righty showed 0 ppm NH3/4+ and 3 ppm phosphate. Today righty tested 8+ ppm and 10+ ppm. The rest of righty's parameters were as expected. pH was 7.6 (the ACO strips always read low), 3 KH, 16 GH (raised by the Replenish) with 60 ppm Ca++ which would make Mg++ around 30 ppm. Conductivity was about 820 us/cm. For lefty, a digital meter showed a pH of 9.8 which seemed to be a bit high for the ACO strip to handle lol. Such a high pH is expected because, not only does microalgae consume CO2, it also consumes carbonate and bicarbonates shown by the 0 KH reading on the ACO strip. To the part that surprised me. Despite receiving the same amount of Seachem Replenish, lefty tested at only 9 GH. On top of that, lefty also tested at 60 ppm Ca++. That means there's only less than 10 ppm Mg++. Does microalgae eat that much magnesium? There always seems to be a point where greenwater cultures just quit no matter how much more fertilizer I add. I figured there was a micronutrient being depleted but didn't know what it might be. Interestingly, the fertilizer I use, Vigoro Citrus, Fruit and Nut, has most of the micronutrient required but it has zero magnesium. Really I don't know yet if it was the Replenish or Vitachem or maybe both that cause the boom for lefty. But so far this seems to point to the magnesium in Replenish being at least a major part of the cause. But I have no idea why they caused the death of righty, may he rest in peace. Second lesson: magnesium exists, eat it up.

Big water changes are usually fine but they can definitely kill weak or otherwise stressed fish or fish that might have a mild illness but aren't showing any signs. I'm not completely sure why. It could be a microbiome change from the treated water which is my working theory or maybe it's an osmoregulatory thing. It happens even in multi-tank systems where water changes are done through the sump so the fish never go through the stress of a gravel vac or the water level in their tank lowering. Exactly this. The way toxicity studies look at one stressor at a time in a lab then report a number makes people think that number matters in the real world. It leads to a lot of bad advise saying "as long as you keep ammonia below whatever specific level..." If ammonia is your only stressor, then sure. But that's very unlikely.

I found a big fat bright red leech in one of my tanks once. Probably came with some blackworms. Never saw another one.

Conductivity or TDS (same thing really) is easy and useful in monitoring the buildup of "stuff" in your aquarium. Otherwise pH and KH are the only other things I regularly test for at home. Once you figure out what behaviors look odd, most of the time that's all you really need. Blackworm are kinda gross.

Here's an example. I recently built a protein skimmer for my outdoor tanks and this is what it's collecting, some kind of dissolved organic compounds:

It seems like this is common with the ACO strips in hard water at least above 250 ppm. I'd just interpret it as "very hard". pH also seems to read exactly 1.0 too low in hard water as well FYI. Everything else seems super accurate regardless though.

I've seen studies on ich that say UV works well for keeping it from spreading between tanks but not so well preventing it from spreading within a tank. This is in lab conditions though where they were careful to properly maintain UV lamps, sterilize equipment used between tanks, and whatnot.

***Freshwater Microalgae (3): "Mixed" vs "Pure" Greenwater*** Although I rarely participate in them, I like to visit other aquarium forums or groups to see what's going on in them. This year I've noticed a trend of trying to keep pure greenwater cultures containing only a single species of microalgae, usually Chlorella, to feed Daphnia, Moina, and other filter feeders. I tried this for a short time but, because I like to keep my home fish related activities as low maintenance as possible, I found it to be a bit too much effort. To justify my laziness, I started questioning if feeding a single species of microalgae is really a good idea. There are, of course, many exception to this but most animals need a varied diet to stay healthy. Ceriodaphnia: A Low Effort Experiment I started testing this with Ceriodaphnia which I previously found reports claiming "mixed" greenwater, usually containing Chlorella and Scenedesmus, being more effective than "pure" greenwater containing only one of these species of microalgae. So I started alternating between feeding greenwater of unknown content and spirulina powder every 4 to 7 day. I saw a very noticable difference with cultures receiving the alternating feed schedule booming much more than anything I had before. However, since this was a low effort experiment, I didn't keep any records or take any photos to show off. Moina: A Not As Low But Still Low Effort Experiment But whether or not mixed species greenwater is better for Ceriodaphnia, that doesn't necessarily mean it's better for anything else. So I did another not as low but still low effort experiment using Moina. I filled 3 jars with different greenwater cultures, added 5 adult and about 15 juvenile Moina to each, and left them sit for a little over a week. (*Microalgae identification is difficult and confusing so take the following IDs as not seriously as you like.) (From left to right: Tetradesmus, Chlorella, wild) Jar 1: microalgae genus: Tetradesmus (a subgenus of Scenedesmus that doesn't form long chains)—grown with snails fed vegetables and old flake food, supplemented with NPK (low P) fertilizer; 0 ppm NH3/NH4+, 0 ppm PO4- Jar 2: (skipped for consistency later on) Jar 3: microalgae genus: Chlorella—grown in recycled Moina culture water (for some reason Chlorella seems to love this); 0 ppm NH3/NH4+, 3 ppm PO4- Jar 4: 'wild" culture grown in open container outdoors, 7 or 8 difference types of microalgae counted—grown with snails fed vegetables and old pellet food, supplemented with NPK (low P) fertilizer; 1.5 ppm NH3/NH4+, 0 ppm PO4- (*By "wild" I mean not controlling the types of microalgae that happen to show up) Results In the above photo (from left to right): Jar 1 (Tetradesmus) cleared out first but much of the microalgae seem to have settled to the bottom. The Moina reproduced but are low in number and most are very small in size. (No jar 2) Jar 3 (Chlorella) didn't seem to clear out at all. The Moina are still in there but they population hasn't seemed to grown much. It's possible they're just hard to see. I'm going to keep this one going see what happens over time. Jar 4 (wild) mostly cleared out with minimal settling. The population grew multiple times the amount of Jar 1 including large, fully grown adults. Conclusion? So the first "not as low but still low effort" experiment seems to show mixed greenwater is better for Moina as well. But there's a lot of different variables that could have contributed to the results. Each jar had different levels of total ammonia and phosphate for example. Jar 1 (Tetradesmus) had no NH3/4+ or PO4- so, depending on how long it's been low, it's possible the greenwater was malnourished. Jar 3 (Chlorella) had no NH3/4+ and excess PO4- which may matter because microalgae tends to store more nutrients in their cells when PO4- is low—meaning the greenwater in this jar may have been less nutritious. Jar 3 was also kind of a double experiment to see if Moina can be grown in greenwater grown in water from a different crashed Moina culture. Jar 4 (wild) had excess NH3/4+ and no PO4- meaning the greenwater was likely well nourished and more nutritious than the others. I do still think it's leaning in the direction that mixed greenwater is better but maybe that's just the laziness bias talking. More experiments to come ...this time including a jar 2 with Scenedesmus.

I know very little about diseases.

Yikes. Get some couch sitting in for me.

If you go to Google Scholar and search "Seachem prime ammonia" or "dechlorinator ammonia" you'll find tons of studies that say in the methods section that Prime or other dechlorinators were used and ~"confirmed to lower free ammonia to safe levels". Most of them mention it beyond that. Here's one related to shipping that used Prime as one of the variables. They confirmed Prime at 20x recommended dose neutralizes 4.5 ppm total ammonia. They used such a high dose to make sure free ammonia levels didn't change as pH changed. You have to download the PDF (link near bottom) to read about how they used Prime, it's not mentioned in the abstract: https://par.nsf.gov/biblio/10299259 Two that specifically tested ClorAM-X (another dechlorinator/ammonia neutralizer) to get more dense, longer rotifer cultures: https://www.tandfonline.com/doi/abs/10.1577/A05-063.1 https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1749-7345.2008.00201.x

By doing toxicology tests with live fish.

Crushed coral can be slow to dissolve. Ideally the baking soda will up the pH and KH and the coral will keep it there. You just have to test every so often see.

Less than 1/8 tsp should bring up KH by 1. You can throw it in or mix. Mixing will give you faster results. I'd test pH, then add a very tiny pinch of baking soda, then test pH again a few minutes later. You want to be careful not to swing your pH up very much at a time with baking soda. I usually go for less than 0.5 pH a day. More isn't a huge deal though

It's true. People before him tested wastewater treatment plants and everyone assumed the same bacteria was everywhere else. Even then the cultivation method used gave very biased results. "Breakthrough" (Hovanec 1998, Burrell 1998). The Burrell study also included Tim Hovanec as an author. There's also one in 2001 about ammonia-oxidizing bacteria. "Decades" of cultivation bias. ("Nitrification" by Ward) Sites earlier Hovanec study in saltwater. ('Design and Operating Guide for Aquaculture Seawater Systems" by Huguenin) For aquaculture but "core taxa exist". There's a lot more studies like this, some with aquariums. They find lots of different stuff in there but around 20% of RNA found is usually from the same bacteria genus (more in the first few weeks) and another 20% or more is from archaea. True. Over 400 species of nitrifying bacteria and archaea have been found. I don't think anyone does that but if they do I agree. Fair enough. Might be worth a try for some people, might not for others. But no one should count on them working 100% of the time.