Surface Agitation - How Necessary?

[David J]

Hi

I am still setting up and not yet started my cycle. Waiting on a test kit which I might get tomorrow. I have my filter (fluval U2) set up. At the moment it is completely submerged and I have it set to the middle spray bar. This obviously creates a slight current in the water and if I look at the surface, there are no waves at all but I can see small particles of debris etc moving around the top in a circular motion so the filters obviously moving the surface but very slowly. Is this good enough? I can raise the position of the filter and set it to the top one which when positioned correctly creates quite a wave.

I am looking to have mostly small fish, the largest being one of the gouramis. I will be going for live plants (java moss, jungle val and anubias).

Thanks,

David

 

[mindwarpstudios]

As i understand it: surface agitation is the key driving force behind gas exchange (Oxygen and Carbon Dioxide being the two we generally worry about).

Setting your particular arrangement is completely subjective to your individual design and requirements, but the principle applies: the more surface agitation you generate, the better the gas exchange will be... another advantage is in regards to films that tend to establish on top of still water, these are not a feature with even minor-to-medium surface agitation.

Personally, I wouldn't set it on "crazy whirlpool"... I tend to be a little more conservative since my plants seem to have a good handle on the O2 generation.

 

[doresy]

Hi, surface agitation serves two purposes.

Firstly, by making ripples this can actually increase the surface area of the water surface by up to double. As this is where the majority of gas exchange takes place this can only be a good thing.

Secondly, surface agitation will stop a film of protein from building up on the water surface which can not only look unsightly but also hinder the gas exchange.

With your type of filter if you are using a spray bar you could swivel it in a slight upward direction which would do the job or raise the whole filter nearer the surface.

I have the pipe outlet of my external filter just below the surface which causes quite a strong ripple which has always suited my stock.

 

[bikerfish]

Hi If you wanted to keep your filter flowing from spray bars in middle then you can always have an airstone and this will move the surface of the water also fish love to play in the bubbles
cathy