Platies biting off Cardinal Tetra tails?!

[martinio1]

Hey, I hope someone can help, this is a bit frustrating.

I have a new planted tank (46L) that has been running now for about 6 weeks. I have had my cardinals for about 2 weeks now. So far so good. No issues, water parameters seem to be ok and I do weekly water changes. 3 days ago, I decided to introduce 3 platies to the tank. I done my research and apparently both types of fish and generally very peaceful and get along very well. I thought great.

The platies were very shy to begin with, as you would expect. The first 2 days I was a little concerned that they were not eating when I was feeding the cardinals. By day 3, they decided to join in a bit and started to eat the flakes that were floating around, so I put a little bit more in and they started eating more. I thought great, now they are eating, feeling more confident, should settle nicely.

As I was watching TV, I noticed one of the cardinals floating rapidly and out of control to the top of the tank and then barely moving. I took a closer look and noticed it's tail missing completely! I thought, ok, maybe it was a one off, but literally an hour later, the same thing but this time, half of the tail was missing.

I'm totally poiting the finger at the platies as everything was ok prior to introducing them, just seems a bit too coincidental. The question is, why? It is simply a case that they think their tails are food so go for a nibble? Just seems strange as I struggle to find anyone with similar issues with platies.

Any suggestions/advice? I have another tank (72L) with 2 gold fish, which are going to be moved soon to another tank (200L). Should I relocate them in there for the time being or find some alternative?

 

[Colin_T]

If the water in the goldfish tank is warm enough and the goldfish are not big enough to eat the platies, put the platies in there and leave the cardinal tetras in their own tank. When you get the bigger tank for the goldfish you can move the goldies out and leave the platies in the current goldfish tank

 

[martinio1]

Thanks for the reply.

The gold fish are around 12cm long (head to tail) and the platies are around 6cm, I think they will be ok. Just need to get hold of another heater. Think I will plan ahead and buy one that is suitable for a 200l tank and just reuse it when they move to the larger tank.

What about feeding them? Will they both be ok on the same food?

 

[Colin_T]

yeah platies will be fine on goldfish food.

 

[martinio1]

Thanks for your help Colin, I will report back once they have been moved and settled in.

 

[martinio1]

Just an update.

The good news:
The platies have been moved into the goldfish tank. The goldfish were a bit curious at first, but the platies just swim circles around them if they get too close. Now they just seem to ignore each other. I created a small area for the platies to give them some cover, but they seem to prefer being in the open. They fed well this morning which is a bonus.

The bad news.
Last night I had done a 30-40% water change on the cardinal tank (water test came back ok). Before going to bed, there was about 8 that I could see swimming around togeather. This morning when I went to feed them, only 2 appeared. Turns out the rest of them had died. I took a look at them and it was 50/50 with some having tails damaged and some looking ok. I'm guessing it was stress that killed the others? Anyway, I performed another water change this morning and some general tank maintenance.

The 2 remaining seem healthy and active, for now anyway.

I'm not going to replace the cardinals after finding out the tank isn't ideal for them. I will wait for now and see what happens before rushing off and buying more fish.

 

[Byron]

I do not comment much on disease issues, but here there are a couple of things. The "OK" parameters, just what are the numbers? And so you know, parameters means GH, KH, pH and temperature; ammonia, nitrite and nitrate are conditions not parameters. That can confuse some of us.

Missing tails can be due to nipping, but also ammonia, nitrite, nitrate, GH and pH.

 

[martinio1]

Ah sorry. I meant nitrate/nirite/ph. My test kit only does the above and kh/nh3/nh4.

I'm not sure what the numbers were last night, but right now:
Nitrite is between 0.01 and 0.025
Nitrite is roughly <0.5
Ph between 6.5 and 7.0
Kh - my test kit (jbl combiset) won't work correct for some reason? The water goes from clear to light yellow. It is suppose to turn blue then yellow/orange? The api test strip reads kh at 0 though.

Tank tempreture is set to 27c. The strange thing is, last night the tank temp dropped to 24.5. It's as if my heater was struggling to keep the tank heated, yet the one I have is designed for up to 120L apparently (fluval e 100w).

 

[Byron]

I'm not sure what the numbers were last night, but right now:
Nitrite is between 0.01 and 0.025
Nitrite is roughly <0.5
Ph between 6.5 and 7.0
Kh - my test kit (jbl combiset) won't work correct for some reason? The water goes from clear to light yellow. It is suppose to turn blue then yellow/orange? The api test strip reads kh at 0 though.

You have nitrite twice,one is presumably nitrate... ? Nitrite is the worry, it should always be zero once the tank is cycled. The pH is OK for cardinals. The two KH are indicating zero so they agree. It is worth knowing the GH which is the more important, but with this KH and the pH I suspect a low (= soft water) GH. But you can check this with your water authority if on city water, their website may have data. Worth knowing.

Nothing direct here to cause tail degeneration but it could have been the cycling. Six weeks is not long, cycling takes from two to eight weeks normally, depending upon factors. If the pH remained below 7 ammonia would not have been an issue. But if nitrite was above zero, this would.

Tank tempreture is set to 27c. The strange thing is, last night the tank temp dropped to 24.5. It's as if my heater was struggling to keep the tank heated, yet the one I have is designed for up to 120L apparently (fluval e 100w).

Heaters often do not set exact temperatures according to the scale/setting. What I mean is, if I set my Jager heater at 24C, it heats the tank to 27C. But set at 22C, it keeps the temp at 24C. This can work in reverse too. Once you find the setting that keeps the tank at the temp you want, it should do so from then on. And adjusting the heater setting requires a few hours before you can assume it is re-set, so it is not immediate in results. And only adjust it a bit each time.

The temp is not the issue with the cardinals.

 

[martinio1]

Thanks for the reply. Good to know about the heater, had simular issues in my goldfish tank, so it makes more sense.

Yeah, Nitrite was 0.01 to 0.025 and Nitrate was reading <0.5. There is no 0 on the scale, 0.5 is the lowest it goes.

EDIT:

I'm not sure how relevent this is, but I did remove the carbon from the filter and replaced it with more bio media. Read that bio media is more beneficial?

 

[Byron]

Thanks for the reply. Good to know about the heater, had simular issues in my goldfish tank, so it makes more sense.

Yeah, Nitrite was 0.01 to 0.025 and Nitrate was reading <0.5. There is no 0 on the scale, 0.5 is the lowest it goes.

EDIT:

I'm not sure how relevent this is, but I did remove the carbon from the filter and replaced it with more bio media. Read that bio media is more beneficial?

The nitrite is still the questionable result...with live plants I would not expect to see either ammonia or nitrite during cycling or after. Maybe the result is just difficult, if test strips, to make out?

Still not sure of the cardinal issue...and not wanting to speculate. Possibles are chlorine (insufficient conditioner?), something toxic in the water, significant changes...??? Have you tested your tap water alone for ammonia, nitrite and nitrate? It is worth knowing if any are present. And is the pH similar between tank and tap water? Remember to out-gas CO2 when testing TAP water for pH, not needed with tank water.

I don't use any filter media except simple sponge in any of my tanks except the 90g canister which has bio max and ceramic disks. These are not needed either with plants, but ...

 

[martinio1]

I've never tested my tap water before. I shall give it a shot and come back with the results.

 

[martinio1]

Well, I ran some tests on the tap water. No traces of ammonium, nitrite and nitrate that I can tell. The 2 remaining cardinals are still doing good.

 

[Byron]

Well, I ran some tests on the tap water. No traces of ammonium, nitrite and nitrate that I can tell. The 2 remaining cardinals are still doing good.

Good to know this. Are you still getting nitrite in the tank water?

 

[martinio1]

Well, I am not getting any more nitrite in the small tank. The issue now seems to be the golffish. They are both behaving erratically. They will be laying at the bottom of the tank (In the corner beside each other) not moving, then all of a sudden, one of them will just freak out and move all over the tank, before settling down again.

I have done water changes. Nitrites is reading 0, Nitrates right now is between 10 and 25 (Says "ok" on the pack but I will do a water change anyway).

I noticed something wrong with their tails/fins. One of them seems to have red streaks in it that I've not noticed before. But they both look similar to the pictures (I could only get pictures of one of them, the other just kept moving around in awkward angles):

The one pictures has always had those colours in it's tail, the other has got reddish looking streaks that I haven't seen before.