Pleco Or Octo For 20 Gallon Tank?

  1. Princethepurplebetta

    Princethepurplebetta Valued Member Member

    Hi guys. I need an algea eater for my 20gallon tank and im not sure if a pleco or an octo would be better (im ok with getting multiple ocotos). The temp is usually 77 degrees, i use sand, live plants, fake wood, and a hob filter. I do 20-30% water changes weekly.
    1 betta
    3 platties
    3 cory cats
  2. bryangar

    bryangar Well Known Member Member

    Look into getting a nerite snail instead.
  3. OP

    Princethepurplebetta Valued Member Member

    Ive had snails in the past and somehow mine always breed. Id rather stay away from them if possible :)

  4. bryangar

    bryangar Well Known Member Member

    Nerite snail eggs do not hatch in freshwater.
  5. OP

    Princethepurplebetta Valued Member Member

    Well ive had them hatch before in my bettas 5.5 gallon :(
  6. Kysarkel000

    Kysarkel000 Well Known Member Member

    Your Cory cats will benefit from having a bigger school. They prefer to be in schools of 6 or more. Anything less will cause them to feel more stressed, and nothing will kill a fish faster than stress. Furthermore, Cory cats will reduce the amount of leftover food that causes the algae to grow, so they help before you even know it (you still need to feed them though!)

    I agree with bryanger, your next best option would to get a snail or some shrimp. If you get shrimp, make sure they have a really good hiding spot!

    Also, is your tank a 20g tall or long?

  7. bryangar

    bryangar Well Known Member Member

    that must’ve not been a nerite snail then lol
  8. OP

    Princethepurplebetta Valued Member Member

    20Long, i will deff get 3 more as soon as the local store gets them in again. The algae is on the glass and decor and the corys dont go near it.

    It was a small striped snail that looked like one. The local store sold it as one. Wonder what it is then
  9. bryangar

    bryangar Well Known Member Member

    They can lay eggs in freshwater, but they won’t hatch. Do you have a picture of it?

    Also Cory catfish aren’t algae eaters, they’re bottom feeders
  10. Leik

    Leik New Member Member

    You said you have live plants. Doesn't plecos eat them?
  11. sfsamm

    sfsamm Well Known Member Member

    I agree a couple or three nerite and address the reasons for the algae and up your number of Cories. As for the algae... You may need more than 20% water change weekly, lights could be on too long, etc.
  12. 86 ssinit

    86 ssinit Well Known Member Member

    Ottos. Gets 3 ottos they will eat the algae. No Cory’s don’t eat algae but they do eat let over food. I’ve had 2 Cory’s in a tank for well over five years. Never looked stressed never got sick. 3 Cory’s are fine together.
  13. Kysarkel000

    Kysarkel000 Well Known Member Member

    Otto's prefer groups of 6+ too. You might have been able to get away will less than 6 Otto's and/or Cory cats, but it depends on the specific species, the individual fish, and their environment. But generally speaking, they seem to do best in large groups. One of the points of keeping fish isint to just keep them alive, but allowing them to thrive.

    I know corycats don't eat algae off the side of a tank, but they are omnivorous. They help clean up leftover food, which if left uneaten will cause extra algae. There will be some human-involved cleaning with every tank. Even if you do decide to get snails or Otto's. It's a sign of a healthy tank. You can try to minimize the amount of algae by giving the tank (an ecosystem) less light, nutrients, more water flow (dissolved oxygen), ect. Getting another critter that eats algae will still need to be fed and may not necessarily eat the algae off the wall of the tank. But it will undoubtedly add to the bioload, adding nutrients for more algae. So it's kind of a gamble. It also depends on the type of algae. Certain critters won't eat certain algae.

    Plecos do not eat live plants. I have a pleco in with my live plants. They will suck on them tho and may crush or rip it apart! Plecos also have a large bioload. You feed them a pea, they poop an apple.

    A snail can make quick work of algae on the side of the tank, more so than a pleco. I don't know about Otto's tho, never had them. There still will be necessary maintenance with any of these options, but I think the snail would be your best bet for sure.
  14. BottomDweller

    BottomDweller Fishlore VIP Member

    What kind of cory are they? Most need cooler water than bettas.
  15. DoubleDutch

    DoubleDutch Fishlore Legend Member

    Agree with the biggest part, only doubting extra bioload will automatically lead to extra algae.

    Btw : I have never seen the proof Oto's should be in large groups.
  16. 86 ssinit

    86 ssinit Well Known Member Member

    Groups of 6 is a wholesalers gimmick. I’ve had both in all different group sizes. I now have 10 emarald Cory’s in a 30 that act like 2 or 3 no difference I never see them schooling. Also 10 in a 90 with same results. Only reason I have so many is they breed like crazy.
    Ottos live on algae the mistake most people make is they buy to many and than they start starving and dying off. Once they start dying all usually die. Ottos are best bought in small numbers. Just enough to be able to eat the existing algae while letting algae grow. Like I said in a 20 3 are all you need 6 or more will finish the algae in a few weeks and than start starving. In my 30 now I have 3 fat ottos that DO swim together and apart. Seems like they like to meet up and than desperse. 4 fat ottos in the 90 for about 8 months now and last night was the first time I saw all 4 together. Thought for months one had died.
    Not here to argue just telling what has worked for me. I do keep these fish.
  17. DoubleDutch

    DoubleDutch Fishlore Legend Member

    Corys definitely show different behaviour in (decent) groups than small groups. Though they might not school tightly they are social fish. There are a lot vids of enormous schools of Corys in natural habitatt. But I don't notice this in my oto's neither did I see such vids. So anxious to know where this info comes from.

    Most Otos that die are wild caught ones that were starved after being caught and transported. Suspecion is that their intestial (bacterial) flora dies of by that.
  18. OP

    Princethepurplebetta Valued Member Member

    Maybe ill try a pleco. The pleco in my 90 gallon doesnt touch live plants at all. What kind would work?
    My corys are the wotori (i suck at spelling)
    Ive had a large group of them in my 90, but all died off now besides one. Hes been fine and somehow is around 15 years old.
  19. oOBlueOo

    oOBlueOo Well Known Member Member

    With a pleco, it'll end up pooping everywhere making the tank dirtier. And some do eat plants. I used to have a bn that preferred Amazon sword leaves over zucchini and algae wafers.

    I honestly just take an aquarium safe sponge and go over the inside of the glass right before a water change. It's so much easier that cleaning up extra fish waste.
  20. DoubleDutch

    DoubleDutch Fishlore Legend Member

    C.wotroi. Ahhhh think they're called C.brevirostris nowadays. Beautiful cory.