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Discussion Starter · #1 ·
Hey all,

I have a 20g dirt tank, low-tech (although can dose Excel if needed), Finnex Planted+ 24/7, and am nearing my cycle completion, so I'm starting to think about which fish to have as my "janitors".

What are your thoughts on combinations of corys, otos, and plecos to have an effective tank-cleaning team (the manual cleaning that I do not-withstanding)?

1. Is 3 corys and 2 otos enough? Some other other combination?
2. Do I need a pleco?
3. What about tossing some shrimp into the mix?
4. Other thoughts and combos?

Thanks in advance for all your expert help,
J
 

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I will probably be in the minority here but having had and still have a standard pleco (now gianormous) and several bristlenose Plecos mine have been all rather ineffective at cleaning anything, rather they lazily demand algae tablets.
Now Cory and Oto seem effective. I have those plus cheap "glass" or "ghost" shrimp to clean uneaten food and Amano shrimp and nerite snails to tackle algae.
(Not in the pleco tank as the even the bristlenose is too large. Pleco tank has clown loaches and giant danios a bala shark and a Angelica Botia loach all which live with fake plants as they would demolish smaller plants lol)
 

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You are gonna want at least 4 otos, otos are social animals and are best kept in groups of at the utmost minimum 4 (my opinion). I don't have a lot of experience with cory's myself but from what I see around here on the forums is that you are probably gonna want 4 of those aswell. From what I have seen is that you could probably get away with doing 4 of each group as corys mainly (correct me if I'm wrong cory experts) eat detrius off of the substrate and don't for the most part clean algae. While your otos will definitely go for the algae.

edit: I wouldn't go for a pleco most pleco's (if not all) will get to big for a 20g tank and their movements might disturbe your substrate. (I have one in a 55 and I think that it might be a little on the small size for him).

Tossing shrimp in is a great idea but be careful and plan around what fish you plan on stocking as a lot of fish will use your shrimp as a meal.

As suggested above nerite snails make a great addition as they don't breed in freshwater (though they still try bless their souls) and are amazing algae eaters. if you aren't worried about a snail infestation ramshorns work fairly well too but they are quiet prolific.
 

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If you just want to keep things clean, go for ramshorn snails, nerites, and shrimp. Ramshorns will eat detritus and leftover food, nerites go to town on diatoms and gsa, and shrimp will eat a lot of softer algae species. In addition, none of those will add too much to the bioload in the same way that fish will or hurt plants.

However, cories are the way to go if you want some entertainment and action on the bottom of the tank, and otos will help with algae as well. I wouldn't really recommend a pleco, based both on tank size and their ability to make a mess.
 

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Discussion Starter · #5 ·
I have a 20g high...

I'm leaning toward 4 Julii Corys, 4 Otos.

Questions:
1. If I do nerita snails, how many is enough?
2. Shrimp, I'm going to to most likely do rasboras/tetras; basic non-aggressive community fish. What are the basic/cheapest shrimp that would be a good choice? And how many should I get? Any special maintenance for them?

Once I add all these creatures, am I still going to be able to add 6-8 schooling fish?

Thanks.
 

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I like ghost shrimps, they are larger in size compare to other dwarf shrimps. I have a 20G and I have about 37 of them. they all hide in the back of my tank, but drop a block of blood worms and they all appear. like a shrimp tidal wave. its actually freaken awesome.

they are not shy either, you will see them fight for food, more like a tug of war with the blood worms. very entertaining
 

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Ditto with leaving the Pleco out of the mix. I have two of what are allegedly bristlenose but may just be common plecos and the only time I see them is when I toss some zucchini or squash in the tank, otherwise they may as well not exist.

If it were me I would solely go for Cory's and Shrimp. Go for a group of each. I would say 4 or more Cory's, but preferably 6 or more would be ideal. They just seem to do better in groups and exhibit more natural behaviors.

Oto's will eat your algae alright, but after that's gone you'll need to be prepared to feed them fresh or a high quality prepared food and hope they'll accept it. Mine never really did and ended up vanishing over a period of months. I haven't tried again. If you purchase your Oto's from the LFS, fair warning they're probably near death already. Ask them what they feed the Oto and if they give you a dumb look and say flake, I would pass because they're surely not actually eating that and are probably not eating anything else. Maybe if you purchase from someone who knows what they're doing and cares about the well-being of their fish you'll have better luck. Definitely don't add them to a new tank otherwise you'll just be paying for the privilege of watching them die.

*Edit* I saw you posted more. I have two nerites in my 40 gallon and another one in my 7 gallon. That was enough for me. Another warning, the nerites tend to leave a trail of white eggs on any surface they feel like. Mostly driftwood, heaters, and broad leaved plants. Your opinion may vary, but I always found that quite unsightly and they don't really disappear without a good scrubbing. That's my only complaint.

Also keep in mind you can purchase smaller cory species to include the pygmy cory, c. hastatus, and c. habrosus. IMO they're just as pretty looking as some of their bigger cousins/brothers but stay a lot smaller so you can keep more of them or other fish.

http://www.tfhmagazine.com/details/articles/corydoras-in-miniature-full-article.htm
 

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I LOVE pygmy cory.
I just ordered 20 from a local middleman.
They are so fun plus a small school of those would be ok in a 20 due to tiny size.
Otos are a risk due to fragility brought on prior to us taking ownership but they are awesome too.
I would say 2 nerrites is plenty for a 20 and you could perhaps get away with one.
Also Amano shrimp are algae destroyers as well.

Sent from my VS985 4G using Tapatalk
 

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Discussion Starter · #9 ·
Thanks all for the great insight an opinions!

OTO/SHRIMP - Regarding a couple of the recommendations above about Otos... I was looking at them, as I'm sure may people do, to take care of any BBA I may have. Will the Amano shrimp eat the same algae? And are they any more or less fragile than the Otos?

CORYS - I have two Julii Corys that my friend was going to give me for my tank, will pygmy's and Cory's function together in groups/schools or should I get all of one species?

FWIW, I went to my local LFS the other day to get some plants, and I was actually considering buying Otos, but the employee that was helping me said I shouldn't buy any Otos until my cycle was complete since they are fragile and particular about the water conditions. So I took that as a good sign. :)
 

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Otos are hit or miss in terms of eating BBA some love the stuff others do not. I have a group of 5 otos in a 20 gallon that mow the stuff down like lawnmowers but my group in a 55 won't touch the stuff. (thus my 20g has become my repository for cleaning BBA plants from my 55)
 

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MOST Oto not all will not eat BBA. The Amanos will. I would say due to starvation and poor handling of Otos by the time we get them Amano is a better bet. They are relatively sturdy creatures. And if this is a relatively new tank DEFINANTLY avoid Oto for now.
Usually only cory of same type will school together and given the depth and width of a 20g (not a lot) I would say do not get full size cory but either Corydoras pygmaeus (Pygmy) or Corydoras hastatus (dwarf) would allow you say 6 or so for a nice schooling effect. Again all of one or the other type. Regular cory will grow too large for the roaming area (footprint of tank base) available.
 

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Discussion Starter · #13 ·
Great info.

I'm going with 6 dwarf/pygmy - skipping the Oto.

How many shrimp is a good number to start with for this size of tank?
 

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Great info.

I'm going with 6 dwarf/pygmy - skipping the Oto.

How many shrimp is a good number to start with for this size of tank?
Never kept shrimp so I'm just guessing, but probably as many as you want within reason. They seem to add a negligible bio load to the tank and they're all relatively tiny.

I did see up above that your cycle hasn't completed? I, and probably many others, would urge you to complete a fishless cycle before adding fish. Doing so spares them from being in a tank with ammonia/nitrites which are toxic in even small amounts and saves you from purchasing fish that may end up dying.

If you choose not to go this route or if you already have fish in there ensure you're doing regular and frequent water changes to combat ammonia and nitrite build up.

Consider reviewing these two posts from an FAQ here:

http://www.plantedtank.net/forums/1960804-post3.html

http://www.plantedtank.net/forums/1960806-post4.html

One for fish-in and one for fishless cycling. Without a doubt both can be done successfully but it's worth educating yourself (if you have already, I apologize!) so that you're well-prepared.

Good luck! Sounds like you have some great ideas. Apologies for coming off preachy, if I have.
 

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Discussion Starter · #15 ·
My cycle just completed tonight! Boom! :) So excited.

Going to put fish in on Sunday.

Thanks again all!
 

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Amano shrimp are not micro and can reach serveral inches in size so maybe 3 or 4?
Of course you could go with cherries and fit alot more in.
Depends what you prefer.
When you choose/setup let's see the pics


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IMO... If it is the "night before Christmas"... Go for 4-5 cories... Any amount of Ghost shrimp... Then wait... Let your tank mature...

Then grab a couple Amano Shrimp... 10-12 cherry... 6 ottos...

Only if your tank is covered, then I would grab a couple of nerite snails... They are escape artist, but can last a bit of time out of water, even on carpet... They are awesome at cleaning your tank of most kinds of algae...

FOOD: I would advise to offer plenty of fresh, blanched veggies(zucchini, spinach, green peas[you will find out that your tank may like some more than others])... Good quality algae wafers...
 
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