Threadfin rainbow questions

Fishstery

Member
Hey there rainbowfish keepers!

I started a 29 gallon last week using an established sponge filter (plus new canister). I dosed the tank to 2ppm ammonia and after 24 hours it was 0 so I took the plunge and finally got a small shoal of 6 threadfins 3 days ago. FyI I will be adding a black ram and two juvenille angelfish tomorrow.

Anyways, the heater I bought for the tank is only doing a so-so job. Definitely not accurate from the temp setting to the actual tank temp, so I'm trying to hammer down what to set the heater to in order to reach 82. Would that be acceptable for my threadfins? When I acclimated them to the tank it was at 80, and unexpectedly I came home today and its 84. I turned the temp down to hopefully hit 82. I prefer to keep my rams at 84, but for the sake of the Angel's I decided 82 was a nice middle compromise.

Next is I heard a lot about these guys being finicky with water parameter changes. Specifically during transport and acclimation. I read a lot about people saying to expect casualties stocking these guys. Let me tell you I paid $11 a piece for these beauties, so I'm nervous. I drip acclimated them from the 7 pH the store has and my 7.8. I lost no fish and they are very active and colorful! However, 24 hours after adding them I checked the water params again to make sure there were no surprises, and my nitrate was between 10-20 (on the API kit the colors are so identical on the card it's hard to differ from the two). Worried about them jumping from adding more fish, I did a PWC tonight and will check them again in a little while but am expecting 5 ppm. Are they too sensitive for 10-20ppm nitrate? My other two tanks never have more than 5 but they are also very established.
 

chromedome52

Member
They're not that sensitive to the nitrates, it's ammonia buildup that can get serious. Definitely not too sensitive for 20ppm; easily tolerate twice that for short periods.

Their temperature range in the wild runs from 22C - 30C (72 - 86 F.), so your temperature should be all right. Bear in mind that the temperature changes slowly in the wild from season to season, and night to day.

Be aware that many sources sell only males, because they are the ones with the fins and color. If you have females, it will be obvious, as they are silver without the long filaments.
 
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Fishstery

Member
chromedome52 said:
They're not that sensitive to the nitrates, it's ammonia buildup that can get serious. Definitely not too sensitive for 20ppm; easily tolerate twice that for short periods.

Their temperature range in the wild runs from 22C - 30C (72 - 86 F.), so your temperature should be all right. Bear in mind that the temperature changes slowly in the wild from season to season, and night to day.

Be aware that many sources sell only males, because they are the ones with the fins and color. If you have females, it will be obvious, as they are silver without the long filaments.
It seems I have 5 males and 1 female. 2 males at the store were very obvious, I tried to have them get me 2 females but it seems 3 of the males are just immature. Definitely one confirmed female because my alpha male has done mating dances with her when they get very excited during feeding. The alpha male actually stays to himself most of the time. They don't shoal all of the time but usually after feeding they group up for a while. I'm really enjoying them. Excited to see how nice my immature males get! I really hope my Angel's tolerate them, and vice versa. If not I will return them and try some praecox rainbows instead.
 

Demeter

Member
I'm reviving your thread if you don't mind

How have the threadfins been doing? I've just put in an order for a group of 8 and I'm gathering experience-based info as I've already scoured the usual care sheets and the like.
 
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Fishstery

Member
Demeter said:
I'm reviving your thread if you don't mind

How have the threadfins been doing? I've just put in an order for a group of 8 and I'm gathering experience-based info as I've already scoured the usual care sheets and the like.
No problem! Turns out I had 2 males and 3 females. I've only lost one (unfortunately one of the males) a few weeks ago most likely due to temperature swings. I have a pellet stove in the basement where the tank is so I don't have the heater plugged in, usually it keeps the tank at a perfect 80 but that day the stove went out so the temp dropped to 76 and then the heater overheated the tank to 84 and the one fell ill. Other than that, they are great. They happily accept crushed flake food and do a great job cleaning up the smaller bits that my praecox rainbows and angelfish ignore. As long as you take extreme care while acclimating (definitely drip method for these) and you have a stable well established aquarium you should have success.
 

Demeter

Member
I was thinking I'd have to drip acclimate based on my researching, only thing I worry about is the ammonia buildup from being shipped. I'll probably add prime to a bucket, dump them in when they arrive then drip acclimate that way. If they get on well I'll have no problems with them, they're going in a 36gal snail/shrimp/nano tank along with 10 new least rasboras to go with my existing 12.

You ever see breeding going on? I might try my hand at raising a batch or two, I even bought some spawn mops just in case.
 
  • Thread Starter

Fishstery

Member
Demeter said:
I was thinking I'd have to drip acclimate based on my researching, only thing I worry about is the ammonia buildup from being shipped. I'll probably add prime to a bucket, dump them in when they arrive then drip acclimate that way. If they get on well I'll have no problems with them, they're going in a 36gal snail/shrimp/nano tank along with 10 new least rasboras to go with my existing 12.

You ever see breeding going on? I might try my hand at raising a batch or two, I even bought some spawn mops just in case.
When there were 2 males I noticed a good bit of mating "flashing" and dancing which was very entertaining to watch. I haven't seen actual spawning but they usually moved into the thick java fern when they danced. They stopped doing it mostly after I introduced the praecox, which are larger and more robust. I would imagine without any larger fish around you might get some success with them spawning.
 
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Fishstery

Member
For entertainment purposes, heres the best pics I could get of the dominant male (they are very fast). One picture you can see him flash that unique dorsal up, acting like a flag to get the females attention.
20191028_174205.jpg

20191028_174214.jpg
 

Demeter

Member
I can’t wait to get them! I’ve been looking into dwarf raimbows but none seem to fit the bill until I came across threadfins, here’s to hoping they arrive safely and acclimate properly!
 
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Fishstery

Member
Demeter said:
I can’t wait to get them! I’ve been looking into dwarf raimbows but none seem to fit the bill until I came across threadfins, here’s to hoping they arrive safely and acclimate properly!
Good luck! Update me once they are settled in!
 

Demeter

Member
Fishstery said:
Good luck! Update me once they are settled in!
They are currently being drip acclimated, all 8 rainbows and all 10 rasboaras are alive and looking good. Only problem is....all the rainbows are obviously males. I contacted the seller after checking the listing to see if it said anything about only selling males. Haven't heard back from them yet but it's still early. Looks like I'll be putting a request in at my local pet store for their next fish order and specifying mixed gender.
 
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Fishstery

Member
Demeter said:
They are currently being drip acclimated, all 8 rainbows and all 10 rasboaras are alive and looking good. Only problem is....all the rainbows are obviously males. I contacted the seller after checking the listing to see if it said anything about only selling males. Haven't heard back from them yet but it's still early. Looks like I'll be putting a request in at my local pet store for their next fish order and specifying mixed gender.
Somehow I managed to get mostly females from my LFS go figure! My male has all the ladies to himself now lol. Still, you had good luck that they all survived the shipping process! I would be nervous about shipping those fish because like yourself, I too did a lot of internet research prior to keeping them and EVERYONE commented about difficulty transporting and acclimating them without any deaths.
 

Demeter

Member
Little update, one pale male died after acting a little off for a few days. I couldn’t find the body but with as many bottom feeders as there are it was gone within hours.

On the plus sife, I found females! Surprisingly my local pet store has a thing for rainbows and they had several species including threadfins. They only had 3 females that I snapped up, they weren’t in very good condition but they are looking much better now. Are your females larger than the males?

1BFE013A-F10A-4BF5-B6BC-EBA939E875B4.jpeg

C4F3DCF4-54B0-4EC3-8B22-D8BD0A3FE477.jpeg

53C20874-7AB1-4705-BCDD-63089E166A5B.jpeg
 
  • Thread Starter

Fishstery

Member
Demeter said:
Little update, one pale male died after acting a little off for a few days. I couldn’t find the body but with as many bottom feeders as there are it was gone within hours.

On the plus sife, I found females! Surprisingly my local pet store has a thing for rainbows and they had several species including threadfins. They only had 3 females that I snapped up, they weren’t in very good condition but they are looking much better now. Are your females larger than the males?

1BFE013A-F10A-4BF5-B6BC-EBA939E875B4.jpeg

C4F3DCF4-54B0-4EC3-8B22-D8BD0A3FE477.jpeg

53C20874-7AB1-4705-BCDD-63089E166A5B.jpeg
I haven't noticed a particular size difference between m/f. It's very easy to get a premature male thinking it was a female, they look very similar so time will tell if you have true females! Mating dances were what told me I definitely had at least one female, another was a premature male. Just keep an eye on those black "threads" if they start to grow longer it's a premature male.
 

Demeter

Member
So things are progressing well and I don’t think I’ll need to buy more females just yet!

Tiny fry upper left corner

218D1DB1-8C2B-464E-B1D2-A4EC555C8E6B.jpeg

Some eggs, several more are on a spawn mop.

86A33455-D5CD-4635-A8C0-D00A48D2A645.jpeg


It’s a 50/50 shot at these eggs and fry being either threadfins or least rasboras. Seeing as I found eggs in the spawn mop I’m leaning towards rainbows
 

RobM

Member
If you can get a good look at yours for comparison, this is a newly hatched I. wernerI eating Sera micron.
 

Demeter

Member
RobM said:
If you can get a good look at yours for comparison, this is a newly hatched I. wernerI eating Sera micron.
I can't get that close of a look at them but I appreciate the video!
 

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