Huge Bubbles At Top Of Tank

[adpgt]

As some of you know, I had OTS. My nitrates well over 180 and now I finally got them down to about 80. Still going to do a couple more 30% water changes to get it down lower.

Anyways, while I was doing a gravel clean today, I put new water in and after a hour, I noticed big bubbles (almost 2 inches in diameter) sitting on top of my tank water. Now, I was wondering if you guys could tell me if they're just normal air bubbles or whether they're nitrogen bubbles. Also, after my water change today, I noticed the fish being a tad more active. One of my bala sharks is really swimming in weird patterns like up and down. I've never seen him do that before.

Pics:

 

[thereverendturtle]

Those are just regular air bubbles, forming from the out flow of your hob. They are just a bunch of little bubbles forming bigger bubbles.

 

[adpgt]

But i've never seen them before.

 

[maurizio]

I'm new in the hobby, so not much experience here, but from what I know bubbles sittingon the surface means an increase of surface tension in the water, and this can only due to external input. In my case, I saw it happen a number of times when feeding the last dusty bits of dried blood worms left in the box. This somehow polluted the water, generating bubbles that lasted some 24 g.
So, it surely is air, but some chemical may be there at work. Just my opinion...

 

[adpgt]

thanks mate!

 

[thereverendturtle]

Are you using stress coat, for your water conditioner, or something similar that's thick? These products will definitely create surface tension.

 

[adpgt]

Not using stress coat but i am using a slimy dechlorifier

 

[thereverendturtle]

Those will often cause the bigger bubbles, as they create a film similar to soap(kinda).