Do plants REALLY need filters?

Discussion in 'Aquarium Plants' started by Pheesh, Apr 11, 2010.

  1. PheeshNew MemberMember

    Hey guys don't filters take out CO2 from the tank which the plants need? Or is it necessary? Do plants thrive more without filters. I also understand you can get CO2 injections into your tank for plants, but wouldn't that just get filtered out by the filter?

    This question came out of pure curiosity :D
  2. NutterFishlore VIPMember

    Plants don't need filters but they do need some circulation from a pump or airstone. If they are kept in completely still water they will very quickly use up all of the available co2 & then not be able to grow. In non-co2 enriched tanks some form of surface disturbance is needed to intoduce oxygen which contains co2.

    Then there are co2 enriched tanks in which the aim is to minimise surface disturbance. Because we are adding co2, the levels of it in the tank are higher than found in the atmosphere. If there is too much surface disturbance, the co2 dissipates from the water in an attempt to equalise with the atmosphere. The trick is to have as much co2 as possible without causing your fish to suffer from a lack of oxygen. (the more co2 in the water the less oxygen it can hold)

    Some filters can cause co2 loss but it depends on the type of filter in question. HOB units & air driven sponge filters create surface disturbance that will dissipate much of the added co2 gas back into the atmosphere. Filters such as canisters or internal power filters stay completley submerged & don't create much in the way of surface disturbance so they do not cause the co2 gas to dissipate to the atmosphere. Using internal power or canister filters is actually a popular way to help diffuse the co2 gas into the water.
  3. PheeshNew MemberMember

    So if i have a CO2 canister is it possible to have both plants and fish without a filter or air stones? Or would that be harmful for fish?
  4. NutterFishlore VIPMember

    If you could control the amount of co2 dissolved in the water & had very light fish stocking, then in theory, yes. In practice, no. The problem is that you need to have some form of current to spread the co2 right through the tank. Otherwise the co2 will only be concentrated in one small area of the tank & will be of no benefit to the plants not in that area. Almost all co2 diffusers rely on having a current to dissolve the co2 into the water to, with the exception of bubble ladders, which don't work very well anyway.

    IMO a filter is needed in every tank, no matter what. Even if it is only a small internal power filter or a tank with no fish, just plants.
  5. NejiValued MemberMember

    I doubt plants need filters. Some say they do just to keep the water a little cleaner, and others say you don't have to. I have seen at my local aquarium store that they have in the tanks some thing with a propeller that pushes the water to the other side causing the water to be moved by the propeller. I guess that would be a really good thing because some plants like the Madagascar Lace Leaf like steady flow of water to push the debree that has gathered up on the holes of the leaf.