tank for JUST plants

  1. midthought Well Known Member Member

    Hi knowledgeable Fishlorians,

    Some background: I am still in the pre-planning stages for what to do with my 29 gallon tank. It needs to be cleaned out, seeded, etc. But I was thinking that I could set up either my 2.5g tank or my 10g tank to house just plants while I get my act together with the bigger tank (which may be several weeks, to be honest). I would probably use the 5g tank I'm currently cycling (fishless), but it's sort of inexplicably running too hot at the moment (details here), and I think putting plants into 80-84 degree water might not work out for most plants. Especially as the plants would probably eventually be transplanted into a much cooler tank. One of the ideas I was considering was putting duckweed and anacharis in the plant tank and then feeding it to goldfish in the 29g. I don't know if I'd want to let duckweed just grow in the 29g with the goldfish, since I'm sort of afraid of them just eating it til they die.

    So my questions are as follows:
    • Is it better to have some fish in the tank, just to maintain a cycle? Maybe some small fish, like tetras? Endlers? Possibly guppies? I mean, are the plants healthier with a cycle?
    • If there are no fish in the tank, how would the water changing schedule go?
    • If there are some little fish in a heavily planted tank, how much time do you estimate the plants buy you in between water changes? That is, how much do they impact the nitrate build up?
    • Without a source of ammonia (fish), the tank shouldn't even start cycling at all, correct?
    • If the tank does start cycling, the plants wouldn't suffer from the tank cycling, would they?

    I am considering keeping some small fish in there mainly because 1) the LFS seems to always have small fish in the plant tanks and that seems to be the norm, and 2) having another tank with a stable cycle makes it easier to seed a quarantine/hospital tank.

    Thanks for your help in advance!
     
  2. pirahnah3 Fishlore VIP Member

    so to answer the 5 questions

    1. It really doesn't matter to the plants, but why not enjoy some fish in the tank
    2. really all your looking to do at that point is maintain a nutrient set in the water column, water changes would only be needed to maintain the levels you desire
    3. Actually in a heavily planted tanks you can really cut back on your water changes as the plants absorb nitrates in the water, I have had heavily planted tanks that I actually leave the tops open on to allow evaporation and that was the only water I added to the tank.
    4. Correct
    5. Not at all, they thrive off these nutrients, actually you want them to have them.
     

  3. toosie Well Known Member Member

    Actually, somewhat of a cycle will naturally occur in a planted tank. As plant matter decomposes it will provide the necessary nutrients to establish a bacterial colony. How large of a colony will depend on how much decomposing matter becomes available. Decomposing roots, stems, leaves, all have an effect.

    Nitrate removal is not the only thing water changes do. Plants like fish obtain nutrients directly from the water as well as what you feed them. Plants can also deplete carbonates from the water. Carbonates/bicarbonates are what makes up KH. KH buffers and keeps pH stable. Plants like fish don't do well when pH drops too low. Water changes also remove other types of toxins that can build up in a tank that we don't and can't test for. Just everyday household chores such as dusting or the use of aerosol sprays can introduce a certain amount of toxins into a tank, especially an open top tank.

    Having fish in the tank may mean you won't have to dose as much nitrates as you will have to without the presence of fish.

    The only time a cycle will harm plants is if ammonia levels are allowed to climb very high. Probably not before 2ppm is present.
     

  4. midthought Well Known Member Member

    That's all awesome information, thanks pirahna and tootsie! I will look into some smaller fish then, as I know not too many would be terribly happy in a 10g...and I'm almost sure only a betta could live in the 2.5.
     

  5. pirahnah3 Fishlore VIP Member

    yeah the 2.5 is gonna be tough, but you could put probably 2 endlers in it or something like that. Need to keep it really small. The 10 would be a bit easier to stock with a few fish.