gardenman

On both Etsy and e-Bay you can find floating plant collections where you get two or three of a variety of floaters. The collections often include a dwarf water lettuce, frogbit, red root floater, or something else. It's a good way to test which works best for you. This is a good time of year to order things as it's not too hot or too cold.

A bichir will get big enough (up to 30") to eat pretty much anything other than a big pleco or a larger catfish. The problem is a 90 gallon tank with a big bichir and some larger Central American cichlids is going to be pretty much at capacity before you add a big enough catfish to survive with the rest. A larger pleco is probably your best option. Plecos come in various forms with some more carnivorous than others. Since your other fish are meat eaters you might want to look into the larger carnivorous plecos as a cleanup option.

Guppies aren't really algae eaters. What you're trying to do is like not feeding a teen-aged boy so he'll go out and chew on the grass so you don't have to mow your lawn. It just won't work. Starving fish in a glass box to try and force them to eat something they don't want to, and really can't eat is not the ideal solution. Feed the guppies and feed them a lot. As for the algae, I've found ramshorn snails to be the most effective algae eaters. Any snail you put in with starving guppies though will be viewed as food by them as it's protein and guppies need protein. You'll have to feed the guppies or they'll eat anything else you put in with them. Feed the guppies, plop in a few ramshorn snails (you won't need many as they'll reproduce rapidly for you) and your algae issues will go away.

Crashes happen. When they do the best thing is to correct the immediate issue, in this case remove the dead body/bodies, change enough water to get things back to a "normal" level (or use an ammonia neutralizer if a water change is impossible) and then put everyone still alive back in to keep feeding the bacteria. Your bacteria didn't die unless you did something stupid, and if it was handling the bioload before the crash it should handle the bioload after the crash. There will be even less bioload as the dead fish is no longer contributing to the bioload. If you're going with a bare bottom tank you might want to consider adding gravel as it'll give bacteria more places to live. Bacteria likes to colonize things and if you have fewer things you have fewer places for the bacteria to colonize. More surface area gives you more places for bacteria to live. Gravel can vastly increase the amount of surface area in a tank for bacteria to colonize. A second filter (sponge or fluidized bed type) can help immensely also. You want lots of housing available for bacteria.

It seemed for a while that everyone was trying to create more oddly shaped fish tanks. There are still some available. You could buy a toilet tank fish tank that would house fish in a tank within the clear toilet tank or inside a clear bathroom sink. All kinds of wall hung aquariums were around. Bettas in bowls hanging from macrame hangers were popular for a while. If there was a way to build something to hold water, someone would put fish in it.

The "trendy" fish these days seem to be the short-bodied fish. These are fish that twenty years ago would have been culled and destroyed as being deformed, but a market has developed for them, and people are buying them at high prices.

I did some poking around and was surprised to read that antlers that are shed (like in deer) are mostly bone once mature, so they could add calcium and trace elements to a tank. Other antlers/horns that aren't shed are more keratin based (think hair) and only have a bony base. I'd avoid the keratin ones but the calcium ones are likely okay.

Part of the quality issue comes down to volume. There are vastly more goldfish keepers in Asia than the US. That makes it a better market for goldfish breeders. A show quality goldfish overseas can have dozens of buyers lining up to buy it at $10,000 or more. A poll on a goldfish forum had three members who'd spent over $10,000 on a single fish. In the US people expect goldfish to be inexpensive. Even the fancy orandas or decent quality goldfish tend not to sell for more than $100 locally. There isn't the same market here as overseas. If you're a breeder, do you take your best stock and sell it where the market is hot or where the market barely exists? If you have a fairly good quality Oranda here and it won't sell at $100, but you'd have people lining up to pay $1,000 for it in China, you sell it in China. That's pretty much true across the whole fishkeeping hobby. Asian arowanas (banned in the US) have sold for as much as $400,000 in Asia. A koi sold for $1.8 million in Japan. (And reportedly died a few months later. Yikes!) Stingrays tend to sell for more overseas than in America. There are just more buyers with more money and willing to spend the money on fish, so the best fish go to Asia. Can you imagine a Petsmart offering a goldfish for $10,000? No. they'd never do that. Most Mom and Pop shops can't afford to do that either. Some dealers (Dandy Orandas being one) have tried to import the higher end, higher quality fish, but getting the sales has proven challenging for them. There are some people in the US who will pay big bucks for the right fish, but by and large they're more into reef tanks than goldfish.

Any of the smaller tetras can be bred in a five-gallon tank. If you go to YouTube and look up "Mark's Aquatics" you'll find lots of detailed videos from him showing tetras spawning in a small tank. They're mostly his older videos as he's more into coastal foraging these days, but he can walk you through the process step-by-step.

The dead and dying algae could have caused an ammonia spike also. Goldfish will seldom suffocate as they can gulp air directly in low oxygen water. When you kill algae it doesn't get teleported away. It dies and starts to decay in the water releasing ammonia. Kill a lot at once and you get an ammonia spike.

It works fine for me. You lose a bit of light intensity, but not that much through the air.

There are lids and there are lids. The typical glass lid can be bad if a fish tries to jump and goes thud on the heavy glass lid. And most fish will jump if startled. It's in their nature. I now use the PVC trim boards to build hoods over the tank that serve as a lid, but the glass/acrylic is well above the waterline (8"-12") giving the fish lots of jumping room before they hit something too hard. The hoods still contain humidity inside the hood/tank, helps keep the tank warm, but also lets the fish do what they do (jump) without getting killed. Plants can grow up out of the water and everyone's happy. A couple of photos of one of my hoods is below.

Odds are your water has some lead in it anyway, nearly all water does, and any gained from the 3D printing would be unnoticed.

Blueberry Oscars are a commonly available dyed fish. Some of the extreme red and yellow Oscars you see these days are dyed also. People want something more colorful and unique, so the unethical dealers provide it. Blood Parrot cichlids with unique patterns/coloring are sometimes produced in such a fashion. If you see something new and unique, you have to be very cautious about how it came about. With koi, sumi develops over years, so if you find a youngish fish with good sumi, it's probably been dyed.

Painting/dyeing aquarium fish, also called "juicing" has been going on forever. Unethical sellers will use a variety of methods to achieve a "unique" color only available through them. Some will inject a dye directly into the fish on repeated occasions to build a color in the fish. Others will first dip a fish into a lye solution to remove their slime coat then dip them into a dye to color their scales. On the more scientific level some will now use a laser and a dye to color a fish. Back in the '60's-'70's Black Moor Goldfish became trendy for a bit and getting a true black Black Moor became almost impossible as every telescope eye goldfish was being dyed/painted black to sell them as a Black Moor. Within a few weeks/months the black would disappear. (And not just because of the normal coloration change of goldfish. In many cases you could see the color peeling off them.) The aquarium fish most likely to be "juiced" these days are goldfish, Corys, plecos, African cichlids, Oscars, and some tetras. It happens with koi also. If a koi is late developing sumi (the intense black) some breeders will "enhance" the sumi to make the fish more sellable. A bit of black ink applied to the scales can add sumi and make the fish more sellable. Done right, it's nearly impossible to detect that the sumi isn't real. The right artificial sumi can take a koi that would sell for a few hundred dollars and make it sell for thousands. A gifted koi painter/juicer can buy cheaper koi, add a bit of sumi, and sell them at a very good profit. It's a buyer beware market out there for fish hobbyists if you see a unique new color on a fish. Dyed fish tend to die young. Those that survive long term will revert to their natural color over time. There are a lot of people out there attempting to con unsuspecting buyers. If a seller refuses to show you the parent fish, it's typically a good indicator that you're buying an artificially colored fish.

You never know until you try. Cichlids are smart fish with personalities. Some personalities get along, some clash. Fish like a Midas cichlid that stake out a territory and guard it from all comers tend to be a problem to keep with anything else unless you have an enormous tank. But even then you'll find an exception or two who gets along with everyone in a smaller tank. You just never know.

If you absolutely, positively know the fish are healthy, will breed true, and there's a market for the fish, it could be a good investment. However, it's impossible to know any of those things to be true and there are a lot of con artists out there preying on people. Fish enthusiasts are often a target for con artists. There have been stories of painted/dyed fish, injected fish, surgically modified fish, and more since I started keeping fish over fifty years ago. I would need an absurdly high-level of trust with the seller to pay $75 per endler. Ideally, I'd want the seller close enough to me and in enough fear of me, to not try and rip me off. They're charging a premium price and given the rate at which endlers reproduce, I'd be suspicious that something was off. Assuming their fish were healthy, happy, well-cared for, they should be up to their eyeballs in endlers and selling them for much less than $75 a fish. If they can't breed them in a quantity, then something's off.

Japanese imported koi and coral for a reef tank is where the serious money is these days in aquariums. It's not hard to spend ten thousand dollars or more for a single koi/coral frag. Collectors are crazy people and a lot of them seem to have more money than brains.

Way back, I kept marine aquariums (in the old Nektonics days of the '70's-80's.) A marine fish was probably the most expensive fish (Mandarin? Rock Beauty? Puffer? Yellow tang?) I ever bought, but it was so far ago I don't remember how much I paid. I don't think I ever paid more than $30 for a single fish though. My "expensive" fish now are Super Red Bristlenose plecos, but I bought them as very young fish (an inch or so long) from Catfishtown on e-Bay and they were on sale. Buy three get three free and he threw in an extra so I got all seven for around $35 shipping included. I had a silver arowana way back, but he was bought as a baby with a yolk sac for less than $10. He cost me a small fortune in food afterward, so buying the fish was the cheap part. Which is always the case. I just spent $6 this morning restocking the green beans for my Super Reds and I'll be doing that again next week. Buying the fish is often the cheap part. That arowana easily cost me over a few thousand dollars to feed him over his lifetime. I had a big gibbiceps pleco that ate the big Banquet food blocks ($3 each) like they were candy. I was buying them by the case from a local pet shop. He cost me about $45 a month to feed. I had him for over ten years. That math works out to around $5400 just to feed him over the ten years. I suspect the pet shop selling me the food blocks mourned his passing more than I did. I see the prices some koi sell for and marvel that anyone would gamble that kind of money on a fish. Someone spent $1.8 million on a koi not too long ago and word is it died a few months later. I'd kill myself if I spent that kind of money on a fish and it died in just a few months.

Kitty litter containers are handy things. I use the jugs that my cats' kitty litter comes in to hold water for topping off the tanks. The jugs are very sturdy, tough, and come free with the litter. If you were to just buy the jugs in a store, you'd end up paying a few bucks for them. You get them free with the litter. It's hard to beat free.

A gibbiceps or sailfin pleco could be an option for you also. They get up to 20" long but stop there. In a 150 that's not too big. They're nice fish too. I had one twenty or so years ago. They're not terribly pricey ($10 and up), quite hardy, tough, long-lived (10-15 years.) If you've got a big enough tank (and a 150 is big enough) they'd be a good option also.

It's always an interesting question. Some say you need to replace trace elements that get used up. Eh, okay. Most quality fish food has an excess of trace elements in them though and whatever the fish don't use gets pooped out into the water to help replenish them. I don't do regular water changes largely because my tap water is so bad. (High ammonia, low pH, no KH.) I've had no issue with fish growth, reproduction, or any of the things you fear. I just top off the evaporation. If you have great tap water that comes out pristine and perfect for the fish you're keeping, by all means change it. If you have to manipulate your tap water to get it acceptable, you can probably get by just fine for most fish without changing it.

Yeah. The same thing here. Eggs get kicked out and moved to a breeder box for me. Once a female lays her eggs, she's out of there. A rival female will sometimes then force her way in, kick out the other eggs and lay eggs of her own. When I find the eggs have been kicked out, I simply move them to a breeder box, add an air stone and wait for them to hatch. Female plecos can get pretty aggressive if there's a male more than one likes.

Most of us probably have been there and done that. It does make sense though. One of the drawbacks of the fine sponge filters is they do clog easily. A clogged fine sponge filter sitting in a tank might just become an anoxic filter. (At least in part. The outer surface would still be doing aerobic work due to the oxygen in the water, but the deeper internal parts might just be anoxic.)

The first place I ever saw or heard of Matten filters was the Swiss Tropicals site. They've been selling them for years and have detailed information there on the use of the filters. You might want to check them out for Matten filter information.