Werid fish behavior

[JL27AY]

Hi ppl,

I notice that a couple of my fishes, mainly the smaller ones are keeping to the top column of my tank the past few nights. I find it weird as these fishes tat i have stay in their respective area in the day my come night they like to get emselves in the way of my powerheads and get blown around, including a few times nearly stuck into my overflow. ANy one experience this b4?

Fishes affected include,

twin spot goby

algae blenny

pipe fish

I tot about it can came up to several reasons.

1. My current too strong? Tank size is 2.5 cube. Got a or6500 as return and two 6045. But the flow is aim in a way the lower part of the tank is slow flow. ie: srooms not blown away.

2. As my rocks are mainly branches, rockscape do not provide enough areas for them to "sleep"? This sounds stupid.

But somehow i believe its possible. as i do not want any dead area in my tank, the rocks are mainly raised my the branches to reduce and areas that block flow. These may in turn create a lack of slow flow areas for em to rest? Make sense?

3. Fish are unhealthy therefore weak and going to up lorry liao.

Possible. But this happened for 3 to 4 days. If really wan to up also up already. During day time all of the above looks okay. Feeding and roaming around.

Water parameters checked and revealed nothing wrong.

Any experts out there?

Cheers