Pale band round Platies

My fishkeeping is now reduced to one 130l tank in which I have Cory's, one BWT and several varieties of Platy - sunset, sunrise, red wagtail, highfins of versions of these. The tank is not very deep but quite long and I have one internal filter and a small spray-bar type of filter to provide water movement (the type used for 25l tanks). As I've got a lot of spare equipment now, I decided to bring a second small spray bar filter into play at the other end of the tank, as the water seems to have less movement there and I did this yesterday afternoon. Last night I noticed several of the Platies appeared to have lost colour around their middle sections so they had a banded effect. Although some of them are pregnant and obviously get lighter around the abdo area, I hadn't noticed it to this extemt before and I'm pretty sure one of the males was affected. I turned the new filter off, just in case, and this morning they are all back to their normal colours. Can this have been over-oxygenation or maybe stress at the additional water movement?

Need a picture.

It's unlikely to be too much oxygen. Water only holds a certain amount of dissolved gasses (nitrogen, oxygen and carbon dioxide). Aeration/ surface turbulence simply maximises the exchange of these gasses and you have a higher level of oxygen, but it will never oxer oxygenate the water.

The sudden introduction of the second spray bar filter caused a temporary stress response in your fish, leading to the loss of colors it looks like a reaction to changes in their environment, they might not like the increased water flow.

It's possible to over gas an aquarium. But it's very easy to notify, all surfaces becomes filled with tiny bubbles sticking everywhere and that is not good.

Not a very good pic - it doesn't show up too well on a camera as it does with the naked eye.

Is the fish eating normally?

Does it still have the pale patch?
If it doesn't, try turning the filter back on and see if it comes back.

As long as the fish is eating well and acting normally it should be fine but it's not normal so monitor and post more pictures if it returns.

Colin_T said:

Is the fish eating normally?

Does it still have the pale patch?
If it doesn't, try turning the filter back on and see if it comes back.

As long as the fish is eating well and acting normally it should be fine but it's not normal so monitor and post more pictures if it returns.

Click to expand...

Yes everything else is normal. It wasn't just the one fish, this is a red wagtail I think, but the Sunrise and Sunset platys are more amber/gold and it was visible in them. I'll keep an eye out for a better photo op. Thanks.