Tlindsey

That was my first thought but hard for me to say definitely. I personally don't see channel catfish for sale especially in the big box stores @D191 Tbh I don't know what type of water that species come from. @Mississippi fish guy

Second pic honey gourami and water sprite plant. The third pic does look like a loach specie. The fourth pic wait for the Tetra with the rummynose to color up and repost. Tbh hard for me to make out the fish in the first pic. @Mississippi fish guy

I personally go the out put of air or appearance of the sponge itself. @Whitecloud09

Yes agree if any gap in the divider the Angelfish will definitely eat the tiny fry.

Yes she is slimmer than yesterday lol. Are the 2 mollies the only fish in the aquarium?

I suggest just add the zebra danio. @Shazoom

Not necessary to rinse filter floss prior to usage.

She looks healthy and pregnant to me. How often do you feed your fish? @rsh

I didn't suggest freshwater pipefish because honestly my pair is not that colorful. The only specie that is colorful are the African Ansorgii freshwater pipefish from Cameroon. I personally have a pair of Doryichthys Martensii freshwater pipefish for about 7 months now. Although not colorful they are very interesting and entertaining lol. @Lennie

I personally kept Seahorses in the 90's. During that time no one not even the lfs used rodi water. I personally mixed distilled water the brand Instant Ocean reef crytals. Had a custom 45 gallon tall setup with a few coral and live rock. My filtration was a small sump and skimmer. The most challenging was providing food for them they ate adult brine. Going to the lfs became a bit much so decided to try frozen mysis. After mixing a few mysis shrimp the live brine shrimp a couple of times was so excited when one started sucking in the mysis. Hopefully now most seahorse breeders feed such non live food. The key to keeping the seahorse healthy is keep their environment stable at all times. You can not slack on aquarium maintenance. I also recommend live rock because seahorse will hunt for copepods. I had custom made metal halide light fixture at that time. Now they make inexpensive led lights for marine setups. I always believe if I could keep seahorse so could others as well. @KaitieG

I suggest purchasing 4. The most important reason is that a greater chance of getting a male and female. Also greater chance for 2 to pair off. A 55gal is fine for a pair. @Tom Perry

@Guppysnail Sorry for your loss.

Welcome to the forum.

The male gourami normally builds a bubble nest. If you noticed him collecting eggs more than likely he has a nest.

I recommend fish that can't be swallowed. The leopard Bushfish has a large mouth. @NOLANANO

Welcome to the forum. Are you doing a fishless cycle or fish in cycle? @Radical

They look like seed shrimp.

Welcome to the forum.

Those are definitely babies. What other fish do you have in the aquarium? @TanTann the fish man

I personally converted a couple of aquariums from saltwater to freshwater. Agree with everyone not difficult. Depending on what biomedia you used it can be used for freshwater. For example I use my bio balls that were once used for saltwater. As @Biotope Biologist stated rinse biomedia very well.

I personally coated a 180 gallon stand build with deck stain to protect it from water and moisture. I honestly don't trust stands made from pressed wood. Almost had a disaster although the stand held for over many years.

Wow pretty intense. I grin when people state the Angelfish is peaceful lol.

That's a nice looking unique stand build. @DallasCowboys16

If you purchased your guppies from a lfs and not a experienced breeder then it could easily be a genetics issue. Most guppies sold to big box stores and some lfs come from fish farms where they are mass produced. This causes issues with health and diseases. I suggest getting the sick guppy out of the aquarium. I would buy a small tote not expensive from Walmart if your in the US. Fill the tote up with water from the aquarium. Place the infected guppy in the tote and add a teaspoon of salt per gallon. @DaniTani

Definitely a female cyclops @Julie63