Greg Stewart

Hard to see defninitively, but it resembles staghorn algae a bit at "this distance". Or, it could be brown diatoms. Has the tank fully cycled? Or, is it still cycling? What are your params, and how frequently do you do water changes?

Depends on the plant. Lots of species do very well in really hard water, others not so much.

It really all depends on the personality of your betta. It's usually safest to add the betta last, or at least after some other fish are there, as there's far less chance of territorial aggression. If you don't have the betta yet, I'd plan for last to be safest. if you have him already, and know his demeanor, it's really up to him how well he does 😉 But, for a 20 long, with proper schools, you're probably looking at 8 to 10 harlequins, 10 or more tetras, 6 corys, the 2 plecos, and the betta. Going by the "1 inch of fish per gallon" thing, you'd be a little over stocked. But, with good filtration and water changes you could probably make it work.

Are you over wintering in a large indoor pond? or, a smaller temporary tank? There are actually a lot of decent options for replacement CO2 diffusers. CO2Art (if you're looking to spend that kinda money) makes a bazooka style in-tank diffuser for large tanks. I use their inline diffuser on my canister filter, and it's very good. JARDLI make some decent glass diffusers for smaller tanks.

My betta has been moved in with 10 harlequin rasboras, 8 celestial pearl danios, 10 chili rasboras, 6 otocinclus, and 10 blue velvet shrimp. I feel really sorry for him, now. He loves to sleep crammed into the intake hose clamp for the canister filter, and the chilis just love to hang out in that same corner, hovering all around him while he sleeps. They also pester him, sometimes, while he eats.

Also need to consider who is in the tank first. When you have a list of good compatible tank mates, it's best to have them in the tank first, and add the betta later. Helps prevent territorial aggression from the betta, since he's moving into someone else's flat 😉

Yeah, not weird. Like xXInkedPhoenixX said, it's most likely biofilm or the stress coat stuff. You can remove it by laying a paper towel on the surface and then quickly pulling it out and tossing in the trash--might need a few goes at it to get all the film. Surface agitation (which bettas don't usually appreciate) will get rid of it, as well.

I still think KittenFishMom was onto something.

This ^^^ Also, since your betta is already acclimated to a populated tank, it will more than likely ignore the shrimp. It may take some interest in them as newcomers, but it shouldn't be territorial with them. Also comes down to what you feed your betta. If he's picky and lazy like mine, shrimp are just too much effort to eat 😉 Corys get along fine with adult shrimp. As everyone else has mentioned, shrimp fry are always at risk in a community tank--even from their own parents, sometimes. And, all the previous advice on hiding spots for the fry can't be repeated enough. Last, shrimp are extremely light on the bioload. So, even if you've maxed the occupants with proper schools of corys and cherry barbs, you should be fine adding shrimp. Go with any colour variety of neocaridina shrimp. they're pretty much the hardiest of the options.

I've used Ich-X, Maracyn 2, and aquarium salt in combo with no problem.

What Torrey said. No need to stress the fish. It seems like you're on the right track just removing the leeches and egg masses you might find. I think they reproduce more slowly than snails, so you might not have to terrible a battle on your hands 😉

Is your GH really 300? I know guppies like harder water, but i usually see 120 to 180 ppm as the target.

Is this the "first leech" or the "only leech" you've found over the past two weeks? If you've found more, I'd just suggest removing them as you see them and getting rid of them. Even if they're a harmless variety, no point having extra waste producers in the tank. If it's the only one you've found since, it may not be anything to worry about. Other than for curiosity.

What Guppysnail said. It's the same with bettas. Also, bettas tend to change colour, sometimes on a daily basis. All depends on the individual fish. As long as the fins are not shredded, disappearing, developing holes, white spots, or other signs of damage or parasites, I think you should be fine. If the colouration doesn't fill in over the next few weeks, try adding some new foods to his diet. (As long as he's not extremely picky--mine is, and it's a PAIN to get him to eat anything other than a single pellet type).

This is probably the root of your problem. 2 to three weeks is exactly the time frame to see acclimation melt. Many people actually trim off all the leaves for crypts and just let them grow acclimated leaves from the start. The melt can have a negative impact on the water params, so if you don't have a test kit right now, that may be a safer thing to to do. Yeah, the EI dosing is a lot. I don't do it. I don't like all that wastage. Over time you get a sense of what your plants like and don't like, and you can' test less often. But, for a new set up it's probably best to get a kit at your earliest convenience. Plants take patience. So far these things look normal in your tank.

@Native Keeper Is that a Crypt Wendtii? How long has it been in that tank? The black spots look like melt. If it's new, it could be typical crypt melt adjusting to the water. If it's older, maybe something has changed in the water/tank. What's your water source? Did that change? If you're dosing Easy Green and can't test for nitrAte at the moment, you can try the "EI" method... dose a crap-ton of Easy Green (for 10 gals i'd guess that's maybe 3 squirts several times a week? 😉 ) and do water changes daily. It's hugely wasteful in my opinion, but lots of people swear by it. EI (estimative index) dosing ensures that ample nutrients are in the water, but inhibits algae growth by removing the spores every day with the water changes. Crypts, though, are sensitive to water quality changes. So, you might check your water source for issues if that plant has been with you a while. You could also try cutting back the leaves and letting it start over. Crypts are good about that.

I've never been successful with monte carlo in a flooded tank. i find the roots to be too fine to plant, and too delicate to glue to a rock. i think dry start, and letting them root themselves is the best way to go. If you have a tank already, and want to add monte carlo, i wonder if dry starting them in a mesh or foam base would be a good idea, so you can position the mesh on the substrate and weigh it down when the MC is ready to move into the tank. I gave up before trying this, though 😉

Pothos is also an excellent nirate consumer. Many people plant them in their HOBs The roots do all the work. The leaves are not submersible.

The first photo does look a lot like anubias glabra, but there are many species that look very similar. Is it a brand new leaf, or is old and yellowing? Anubias grow very pale new leaves. Crypts may also, but I have no experience with them. If it is an anubias, just let it grow, that leaf should darken as it matures. The bottom photo could be a crypt, but I can't see what discolouration you're referring to. It's a bit blurry, and my eyes are horrible.

I haven't used API CO2 booster, but I do use Seachem Flourish Excel. Both products are based on gluteraldehyde, which is actually an algaecide. They do provide *some* available CO2, but you won't get a "good replacement" for injected CO2 by using a liquid carbon product. I've found that plants just don't respond the same way to gluteraldehyde provided carbon as they do to actual CO2. Also, some plants are sensitive to it, and over dosing either of them can cause some melt in sensitive plants. That said, I do use Excel when quarantining plants to keep them on at least some available carbon. But, I find that it's better for spot treatment of algae growth on slow growing plants (I have to remove my anubias and some of my bucephalandra about once a month, and gently wipe a bit of Excel on the leaves and return it to the tank to clean off spot algae grow--i have them a little too exposed under the LED lamp).