Planning my next large aquarium - Semi-aggressive

[IHaveADogToo]

So, I'm about to have a whole lot of space free up in my house. And I can get some pretty big tanks on Craigslist for cheap. So I'm looking at 55 gallon and 75 gallon tanks for my next big project. It will be my largest tank yet, and I plan on using it for semi-aggressive larger species.

I'm just in the planning stage now. Nothing has been purchased yet. I don't have any of the fish for this tank yet. But I'm looking for input from community members.

So far, I know for a fact that in that tank I want:
1 Rainbow Shark
1 Peacock Eel
2+ of Angelfish (I'd really like to have two pair)

And that's all I have planned.

I will, of course, use sand substrate, as Peacock Eels like to burrow.
Also, I know the Rainbow Shark will want a cave. I can do that.
But what else should I do?
Should I use live plants? Or will the Eel uproot them? Would rocks and diftwood and maybe some fake plants be better?
Do I need to go for the 75 gallon tank, or would a 55 gallon be sufficient? I don't want to have to upgrade someone's tank later.
I know every fish I mentioned likes a lot of space, so should I restrain myself from overdecorating?
Is my desired combination of Angelfish, Rainbow Shark, and Peacock Eel raising any compatibility flags? What other compatible tank mates would compliment this combination? I don't want something that will eat its tank mates over the years, like an Arowana would, for example.

Thanks in advance. Looking forward to everyone's input!

 

[hobby5]

Hi there!

With aggressive fish a tank never can be too big, so always get the larger one. Imho those tanks are not big at all and I consider 75G too small for a proper Angelfish tank, meaning not only keeping a matched pair or a single angel. I cannot comment on the other two species as i have no experience with those.

With aggressive fish decoration is important. You need to break lines of sight and provide ample hiding places. Go for live plants! They add so much to the biology of your tank and the well beeing of your fish.

 

[IHaveADogToo]

Thanks for the reply!

You think 75 Gallons is too small for angelfish? Really? I know the bigger the better, but surely the minimum is a reasonable size. What size would you say is the minimum?

I do have live plants in all my tanks now. I agree, it's just better for the fish. But like I said, I'm concerned that the peacock eel will uproot plants by burrowing. It doesn't sound very fun to have to "fix" uprooted plants every day, multiple times a day.

 

[AbbeysDad]

I'm gonna disagree. I have two Angels (I think male brothers) in my 60g with several other fish and they're doing just fine. A 4 foot length with a 24" height is fine for them. Besides, they live in fresh, clean water with lots of living plants and are fed well with no predators!
I can't speak to eels or sharks and as they get bigger, I would suspect that they'd be happier in a bigger tank than 75g. I cringe and feel sad when I hear of or see big fish in small tanks....just as I do seeing lions and tigers pacing back and forth in 10x20 cages. We place a lot of stock on freedom (or the feeling of freedom [we do pay taxes!]) and It just seems wrong to confine animals in such small spaces.

 

[Colin_T]

How big are the tanks, length x width x height?

rainbow sharks grow to about 4 inches and are fine in tanks 3 foot or longer.

if peacock eel is Macrognathus siamensis, they grow to about 8 inches and are very peaceful and do not disturb plants. They prefer to be in groups and spend all day buried in the substrate so use sand for them.

Angelfish can get to 4-5 inches but a pr will be fine in a 3ft long x 18inch wide x 18inch high tank or bigger.

None of these fishes are aggressive. If you want a real agro fish get a sooty grunter from Australia, they kick hell out of big African cichlids just for something to do.

 

[IHaveADogToo]

None of these fishes are aggressive.

They are all labeled semi-aggressive, though, for whatever reason. I know angels (and rainbow sharks) can be quite territorial. Rainbow sharks will indeed be aggressive towards their own kind if kept in groups smaller than 5 or 6.

if peacock eel is Macrognathus siamensis, they grow to about 8 inches and are very peaceful and do not disturb plants. They prefer to be in groups and spend all day buried in the substrate so use sand for them.

How can a fish be a burrower and not disturb the plants, though? Burrowing, in itself, would disturb the plants, wouldn't it? And yes I definitely would use sand. I hadn't heard about keeping peacock eels in groups though. Everything I've read about them says they *can* be kept together, as long as they're the same size as each other, but I haven't read anything that says they *should* be kept together.

As for tank dimensions... they vary. Like I said, I haven't bought the tank yet. I'm just looking at Craigslist because there are a lot of people trying to unload their old aquariums for super cheap. But it sounds like I definitely want a tall, long tank. Tall for the angels, long for the shark.

I can't speak to eels or sharks and as they get bigger, I would suspect that they'd be happier in a bigger tank than 75g. I cringe and feel sad when I hear of or see big fish in small tanks....just as I do seeing lions and tigers pacing back and forth in 10x20 cages. We place a lot of stock on freedom (or the feeling of freedom [we do pay taxes!]) and It just seems wrong to confine animals in such small spaces.

I understand, I feel the same way when I hear of or see a betta in a 1 gallon tank or a vase. I certainly don't want to be the guy who's tanks are too small for his fish. Everything I've read on peacock eels, though, says they need at least 35 gallons, so pardon my surprise when I hear 75 gallons isn't enough. The eels get about a foot long. The rainbow shark maxes out around 6 inches. Since the shark needs a bare minimum of 50 gallons, and the eel needs a bare minimum of 35 gallons, are you saying 75 gallons isn't enough for these territorial creatures to coexist? I suppose I can see that, especially with a pair of angelfish in there as well. If this plan isn't going to work, it's best that I know now before I create a situation I can't get out of. Maybe it would be better if I do this without the shark...?

 

[Colin_T]

Rainbow sharks are only territorial towards others of their own kind and in small tanks where they don't have enough space for their own territory.

Angelfish fight among themselves and the best way to buy them is in a group of 8-10 young fish and grow them up together. When they mature and pair up, you keep a nice pr and remove the rest. Depending on tank size, you can keep 10 adult angelfish together.

Macrognathus siamensis are very peaceful and don't dig up plants. They can disappear into the substrate very easily and don't damage plant roots. They do however, jump so you need good covers on the tank to stop them going awol at night. We use to keep them in tanks about 2ft long x 18inches wide x 18inches high and they bred in those tanks.

There are other types of eel and some of them get bigger and do fight, but the species above is peaceful.

A 75 gallon tank is ample space for these fishes to live together.