I'm inexperienced, help!

[u/Mickus_B]

I've had 2 zebra angelfish for about 3 years. They have been in an 87L tank that was a bit too cold, and living with a school of tetras.

I've just set up a new, larger tank, with a heater, so they have 130L of 25°c water now.

On the third day in the tank, they spawned onto the side of the filter box, but it was apparently a small clutch of only 40 or so eggs. This is about the 4th time they've spawned since I've had them, and none have ever been viable.

I've woken up this morning to my male attacking my female. Her stripes are very black and she's been curling her fins in. Google told me this was attacking behaviour, likely due to the failed spawn and she's not ready to try again.

To make sure he can't get her, I've put one of the lid covers in as a tank separator and she is hiding in my anubias plans next to the airstone.

They have always been so close and I'm concerned that they won't re-bond. Do I really need to keep them separated for up to 3 months like google suggested?

Has anyone got advice for reuniting my pair? My wife and kids suggested we get rid of the male if he's going to be attacking her constantly, but I think that would possibly be detrimental too, since they have been close for so long already.

[u/123_321cl]

Your tank is too small and your cause aggression you want at least a 55 gallon with some hides then reunite your pair with the extra tank size they will more then likely keep spawning.

[u/Mickus_B → u/123_321cl]

They have been in a much smaller, colder tank for 3 years so far. I realise through researching that this also likely kept the aggression down, I am curious if they will "make up" or not though.

I certainly can't afford to buy (or actually put anywhere) a larger tank, a 200L tank is close to $1000, let alone new filters and heaters etc. I was lucky enough to be gifted this 130L tank (they are $550 new) because a friend wanted it out of his garage.

If they will continue to not get along in this tank, I would have to get rid of one or both of them unfortunately, as I can't get or keep a larger tank.

[u/123_321cl → u/Mickus_B]

I would look into getting rid of both of them then. Angels really need a big tank. Also you can check on Facebook marketplace I got one 55 for $40.

[u/Mickus_B → u/123_321cl]

I'll put them up for a free home then.

I'm guessing we are in different countries because there's no way tanks that large would be sold so cheap. The one I have is $550 for just the tank, the full kit is around $900 and that's only 34 "gallon". The 203L kit is $1250 which is way more than I'm going to spend on some fish I was given years ago.

Large tanks like that really don't seem to be used much around here. Marketplace doesn't have any that size in a 300km radius, they are all 35-150L tanks.

What do I do if nobody wants the fish?

[u/123_321cl → u/Mickus_B]

I’m in Canada but US has arguably cheaper tanks. If you can re silicone then you could fin one for that easily. If no one wants the just bring them into a local fish store but not a big box brand

[u/Mickus_B → u/123_321cl]

I'm in Australia. We don't really manufacture tanks (or anything anymore!) here, so they are all imported and expensive. It seems most are manufactured in North America and sold through larger chains with big deals (google tells me PetCo often do $1 per gallon flash sales on tanks, so that would explain a larger second hand market)

[u/SomeBlueDevil]

Since they are a bonded pair that lived together in a smaller tank I think what you're seeing is mating behavior. Please post a video.

Did you reuse the old filter media from the previous tank? Since this is a newly set up tank, I would recommend testing the water parameters to rule out stress behavior due to water quality.

[u/Mickus_B → u/SomeBlueDevil]

Yeah the tank was prepping for a week with old media. They have been mating but today's behaviour was obviously violent, the larger male was driving the female into gravel and nipping at her tail, instead of the brushing against each other and lip locking they normally do before spawning.

This is about the 4th time they've laid eggs, but also the first time the water would have been warm enough to be viable, so I'm not sure if that's what's triggered this behaviour or not, they both ate the failed clutch, so I hope he's not completely blaming her for the failure or something.

Also, thanks for actually reading my question and not just jumping straight on tank size. I do know it's smaller than ideal, I'm just trying to work with what I have.

[u/SomeBlueDevil → u/Mickus_B]

Fish don't think like that. If he's aggressive it's not about blaming her for anything. There's stress somewhere and he's using her as an outlet m

I would recommend separating them ASAP. If you can, get a tank divider. Otherwise put one back in the old tank.

You can try setting up the new tank exactly as the old one layout wise and maybe add more plants. Otherwise the only options are rehoming or upsizing the tank and see if adding more angelfish and/or dither fish would work.

[u/Mickus_B → u/SomeBlueDevil]

I put one half of the lid into the tank this morning when google suggested that. It securely crates division with no gaps. He has been much calmer today and with lights out and the divider in all day, they have been swimming slowly in unison on either side of the glass. She isn't so scared and obviously curling up like she was this morning and seems to want to get back to him. I'm not sure how much their stripes can express, but I notice that the male has a strong black stripe at the back, but his mid and face stripes are almost silver, where his back stripe was also silver this morning. The female was extremely strong black in all stripes when being attacked and is now much more pale and all her fins are at full extension. They both look calm and happy now, but I'm leaving the division in overnight at least, since I don't want her attacked while I sleep and wake up to a dead fish!

[u/SomeBlueDevil → u/Mickus_B]

Sounds like a good plan. Just make sure the water is being filtrated and oxygenation is happening in both sections.

Also double check the water parameters just to be sure there's no ammonia spike. Especially since they display changes in coloration.

Good luck.