Corys and mixed substrates

Seisage

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I heard there was some desire for a thread about utilizing mixed substrate strategies with corys and I figured I'd start one because I also have some questions.

My text tank project after the Ucayali biotope will almost certainly include some kind of cory. I already have a big bag of fine sand, so I'll definitely be using that, but I was wondering if anyone's housed corys in a layered substrate setup that has a sand cap. I'd like the tank to be pretty heavily planted and I've heard that plants tend to not like really fine sand because it's harder for them to push their roots through, so I would potentially want to consider a base layer of dirt or gravel, with a couple inches of sand on top. Would the corys dig and sift in the sand deep enough to disturb the lower substrate layer and cause mixing?

This thread can also be used to talk about other ways to mix substrates for corys. I do think the little sand beach technique is really cute :)
 
I would think that if the dirt is low enough below the sand/rock subtrate that the cory wouldn't be able to really distrub it. They don't really dig, but rather sift the top layer. If you had something like a kuhli loach then that would definitely dig into the substrate.
 
Thank you for starting this! I had another tab open, telling myself to do it since I offered to make one, then got distracted reading the same threads as you I think, haha, and now undecided about what substrates I want to use and try in my replacement set ups! @realgwyneth , Seisage made the mixed substrate thread, ask away! Also love to see a photo of your tank if you want to share and let us know what you'd like to do about adding a sand area, and we're not hijacking JackGulley's thread here. :D

I have fine pale unipac sand, courser black limpopo sand, and a couple of bags of Argos play sand, and some tetra planted substrate stuff, and tempted to try tiers, mixing different substrates, and also wanting to try a planted or dirt substrate, for the plants I couldn't keep in fine sand, and because I'm forgetful about root tabs and liquid ferts. :blush:

But, cories do dig, and they uproot smaller delicate plants often, for me. I also kinda want botiid loaches, and I'm sure they'd dig too, and my plecs might contribute to the problems of mixing substrates, and uprooting stuff.

So now I don't know what I want, but excited to try some new things! :D

@Wills , you do gorgeous tiered stuff, and mix substrates too (I highly recommend checking out his and @WhistlingBadger 's journal threads!)

so I would potentially want to consider a base layer of dirt or gravel, with a couple inches of sand on top. Would the corys dig and sift in the sand deep enough to disturb the lower substrate layer and cause mixing

Can't really do sand on top of gravel even without bottom dwellers digging, since over time the sand will naturally sift down and settle lower than the larger gravel anyway, but especially with cories or other diggers milling around over it. Maybe a planted substrate/dirt with a sand cap? I don't know enough about how people separate the layers I'm afraid, but others know way more, hopefully they'll share their secrets. ✨
 
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Just make sure not to get these ones 😂
I love how much fun the cory is having, but yeah!! Not great for delicate plants that don't have decent roots.

rotela, hydrocotyle, sword.JPG


pre-adding cories, the rotala front left had been doing beautifully and thriving, and the hydrocotyle tripartita "Japan" (I'm butchering the latin, but tired and too lazy to search, sorry!) on the right was a dream plant for me since I saw this video:


It's like clover! And so trainable. It was doing well, and I began trying to push the new strands in around a coconut hut, trying to give a little fairy cottage look
hydracotyle coconut hut.JPG


But then I had I think seven bronze cory young from my first surprise spawn, added them to this tank, and regretted it! Constantly uprooted the rotala until I got sick of attempting to replant the failing stems, and the hydrocotyle hung on for longer, and was forgiving enough to keep growing even when floating, but it's a creeper type plant. Long trailing stems like runners, with a few thin delicate roots, so it could never settle and establish, just got uprooted and replanted a billion times, smaller and smaller, tangling in the other plants once left to float, and I don't think I have any left now. :(

rotela failing and sword taking over.JPG


Look how sad the remaining rotala stems were by this point 😭 and it got worse and more pathetic until the last ones died.

Love my bottom dwellers and cories, also love planted tanks, and you can have both, but definitely have to consider plants carefully.

liliopsis grate.JPG


That one above was a liliopsis of some kind I added to cart on impulse, then found it's almost like a grass, but with less roots. So I did some googling, ended up supergluing it to a metal grate that I'd bent the edges on so the cories wouldn't hurt themselves on it when they dig, and buried the grate pretty deep in the sand. But between plecos and cories knocking it about and digging, I'd fine more and more of the leaves floating on the surface, and it lasted about a week I think.

I tried so hard!! 😭:lol:
 
I love how much fun the cory is having, but yeah!! Not great for delicate plants that don't have decent roots.

View attachment 336866

pre-adding cories, the rotala front left had been doing beautifully and thriving, and the hydrocotyle tripartita "Japan" (I'm butchering the latin, but tired and too lazy to search, sorry!) on the right was a dream plant for me since I saw this video:


It's like clover! And so trainable. It was doing well, and I began trying to push the new strands in around a coconut hut, trying to give a little fairy cottage look
View attachment 336867

But then I had I think seven bronze cory young from my first surprise spawn, added them to this tank, and regretted it! Constantly uprooted the rotala until I got sick of attempting to replant the failing stems, and the hydrocotyle hung on for longer, and was forgiving enough to keep growing even when floating, but it's a creeper type plant. Long trailing stems like runners, with a few thin delicate roots, so it could never settle and establish, just got uprooted and replanted a billion times, smaller and smaller, tangling in the other plants once left to float, and I don't think I have any left now. :(

View attachment 336868

Look how sad the remaining rotala stems were by this point 😭 and it got worse and more pathetic until the last ones died.

Love my bottom dwellers and cories, also love planted tanks, and you can have both, but definitely have to consider plants carefully.

View attachment 336869

That one above was a liliopsis of some kind I added to cart on impulse, then found it's almost like a grass, but with less roots. So I did some googling, ended up supergluing it to a metal grate that I'd bent the edges on so the cories wouldn't hurt themselves on it when they dig, and buried the grate pretty deep in the sand. But between plecos and cories knocking it about and digging, I'd fine more and more of the leaves floating on the surface, and it lasted about a week I think.

I tried so hard!! 😭:lol:
Oh man.. I didn't even think about plant uprooting... Are there any plants in particular that you'd avoid with corys? I was planning mostly for stem plants, maybe an amazon sword or two, some buces, and potentially some crypts.
 
Oh man.. I didn't even think about plant uprooting... Are there any plants in particular that you'd avoid with corys? I was planning mostly for stem plants, maybe an amazon sword or two, some buces, and potentially some crypts.

All of those would be fine with cories, so breathe a sigh of relief! ;)


What size tank are these plants for?

Amazon swords are great, can grow huge, root deeply, and are greedy root feeders. Crypts are also greedy root feeders when given the chance, so you definitely want some root tabs for the sword(s) and crypts, so they grow well and get those roots down and established. Would be worth giving them, and all the plants really, at least a couple of weeks to begin rooting properly before adding the cories. ;) But it's amazing how much growth they can put out in a week. I like to take photos each week when setting up a new tank, just to see how much they perk up and grow in a short time. It helps when I'm feeling impatient waiting for it to fill out, since seeing it daily makes it harder to spot, but compare a photo from the previous week to the next, and the differences and amount of growth/perking up are much clearer.

Crypts are a wonderful plant species! While they are greedy root feeders when given the chance, they're also hardy and forgiving, so even without root tabs they'll usually take enough nutrients from the water column to steadily grow and hang in there. They'll just grow better, bigger and faster with the addition of root tabs now and then. :) They can grow pretty elaborate root networks which produce more and more baby plants, or that can be split and planted elsewhere as the plant gets bigger and produces more offshoots.

There is a thing to be aware of with crypts though, especially when transplanted like when you buy one and plant it in a new tank. There's something called "crypt melt", where your beautiful new crypt just melts away to nothing, and people think it's dead and chuck the remains. Don't! They do it sometimes (but it may not, they don't always melt back) because they'll grow back just from some roots, so leave the roots and wait for those first new leaves to emerge if you do experience crypt melt. :D

Buces, anubius, java ferns and all the other rhizome plants like bolbitis aren't a problem with cories. Ditto mosses, floating plants etc, since they're not planted in the substrate (the rhizome must not be buried, or it'll rot and kill the plant), so are usually attached to hardscape, or poked into holes in the hardscape and can establish themselves there. All good choices, low maintenance, easy beginner plants. :)

Oh, any bulb based plants also fine with cories. Crinums, lotus... um, can't think of any other bulbs right now, but there are others, haha. But those are more secure and usually root pretty well too.

When you say stem plants, which do you mean? If you mean fast growing stem plants like elodea, hornwort, water sprite, guppy grass, limnophilia sessiliflora etc, then they'll also be fine with cories, since they're fine with floating or being planted, and some root more easily than others, but aren't delicate plants that'll struggle if the cories knock them about like my poor little ones I cried about above, lol.

The ones I'd avoid are more the expensive, harder level and delicate plants, like carpeting plants... But any plants you're interested in are worth checking out on the Tropica website, which gives more info about difficulty level, whether it'll require CO2 or high lighting, and Tropica often have videos about different species too.

I love this one, and recommend it a lot, I miss having it! I kept growing mine into a dense hedge around the sponge filter to hide that from view, and the fish and shrimp love this plant too. I love the way it changes colour and looks like fluffy clouds as it reaches the surface 😍

Oh, make sure to add some kind of floating plant to your list. Anything but duckweed, avoid duckweed like the plague, and be merciless if any appears in your tank and remove every trace. It's a nightmare. Anything else is okay, anything but duckweed! (can you tell I hate duckweed? I really, really hate duckweed!)
 
All of those would be fine with cories, so breathe a sigh of relief! ;)


What size tank are these plants for?

Amazon swords are great, can grow huge, root deeply, and are greedy root feeders. Crypts are also greedy root feeders when given the chance, so you definitely want some root tabs for the sword(s) and crypts, so they grow well and get those roots down and established. Would be worth giving them, and all the plants really, at least a couple of weeks to begin rooting properly before adding the cories. ;) But it's amazing how much growth they can put out in a week. I like to take photos each week when setting up a new tank, just to see how much they perk up and grow in a short time. It helps when I'm feeling impatient waiting for it to fill out, since seeing it daily makes it harder to spot, but compare a photo from the previous week to the next, and the differences and amount of growth/perking up are much clearer.

Crypts are a wonderful plant species! While they are greedy root feeders when given the chance, they're also hardy and forgiving, so even without root tabs they'll usually take enough nutrients from the water column to steadily grow and hang in there. They'll just grow better, bigger and faster with the addition of root tabs now and then. :) They can grow pretty elaborate root networks which produce more and more baby plants, or that can be split and planted elsewhere as the plant gets bigger and produces more offshoots.

There is a thing to be aware of with crypts though, especially when transplanted like when you buy one and plant it in a new tank. There's something called "crypt melt", where your beautiful new crypt just melts away to nothing, and people think it's dead and chuck the remains. Don't! They do it sometimes (but it may not, they don't always melt back) because they'll grow back just from some roots, so leave the roots and wait for those first new leaves to emerge if you do experience crypt melt. :D

Buces, anubius, java ferns and all the other rhizome plants like bolbitis aren't a problem with cories. Ditto mosses, floating plants etc, since they're not planted in the substrate (the rhizome must not be buried, or it'll rot and kill the plant), so are usually attached to hardscape, or poked into holes in the hardscape and can establish themselves there. All good choices, low maintenance, easy beginner plants. :)

Oh, any bulb based plants also fine with cories. Crinums, lotus... um, can't think of any other bulbs right now, but there are others, haha. But those are more secure and usually root pretty well too.

When you say stem plants, which do you mean? If you mean fast growing stem plants like elodea, hornwort, water sprite, guppy grass, limnophilia sessiliflora etc, then they'll also be fine with cories, since they're fine with floating or being planted, and some root more easily than others, but aren't delicate plants that'll struggle if the cories knock them about like my poor little ones I cried about above, lol.

The ones I'd avoid are more the expensive, harder level and delicate plants, like carpeting plants... But any plants you're interested in are worth checking out on the Tropica website, which gives more info about difficulty level, whether it'll require CO2 or high lighting, and Tropica often have videos about different species too.

I love this one, and recommend it a lot, I miss having it! I kept growing mine into a dense hedge around the sponge filter to hide that from view, and the fish and shrimp love this plant too. I love the way it changes colour and looks like fluffy clouds as it reaches the surface 😍

Oh, make sure to add some kind of floating plant to your list. Anything but duckweed, avoid duckweed like the plague, and be merciless if any appears in your tank and remove every trace. It's a nightmare. Anything else is okay, anything but duckweed! (can you tell I hate duckweed? I really, really hate duckweed!)
This is going to be a 20gal long! So ~90x30x30cm. Good to know about the amazon swords. I knew they were somewhat larger plants, but considering it's a slightly shallower tank and I'll probably have a couple inches of substrate, they might actually get too big! Plus I'd love to not have to deal with a bunch of root tabs if possible.

As for stem plants, I mean the fast-growing plants that take nutrients from the water column. I'm thinking things like bacopa, ludwigia, pogostemon, and maybe rotala and egeria. That limnophila is really pretty too! I definitely want them planted (not floating), but giving them time to establish will probably help them stay that way. I was definitely assuming I'd have to and would plan on it. Keeping them in the background behind driftwood and amongst river rocks will probably also help keep the corys away from the roots, I'd imagine. I knew about plant melt in general, but good to know crypts are notorious for it lol. And I'm glad they'll do okay without root tabs if I end up forgetting to give them some every now and then.

I actually didn't know buces were rhizome plants! That's fantastic news and makes my life even easier. I'm also planning on some anubias nana, which I was going to put on whatever driftwood I have in the tank. I'll stick the buces on some rocks or something then! The floating plants will be a given. I love having them for their nitrogen greed. I'll probably stick with water lettuce for this tank. They're not quite as fast growing, but I really love the way their roots look and I don't need to trim them every week like my frogbutt (that started out as a typo, but honestly frogbit is kind of annoying, so now it'll forever be frogbutt to me).
 
Thanks for starting the thread @Seisage! I would love to see some photos, in addition to @AdoraBelle Dearheart's, of tanks with mixed substrate, in particular gravel and sand. We've always had gravel in this tank and its predecessor, but we've fallen in love with Schwartz corys. They're thriving on the gravel, but I know they would be happier on sand. But the tank is planted, though many of our plants haven't been successful. Now that I read y'all's posts, I wonder if the corys have been uprooting them. Anyway, we've been dreading the process of replacing the gravel because it sounds so onerous, so we keep putting it off. Now that I know we can just replace a portion with sand, I think we're going to give our corys a sand "beach." They'll have their sand, and the plants that are well rooted can stay in the gravel. Maybe over time, the sand portion will grow and the gravel portion will shrink.

This is a 65 gallon tank, so 36" x 18" x 24". It's really tall but it has lots of swim room for tetras and barbs. I'd love more stemmed plants to fight the algae for nutrients, but we haven't had a lot of luck. We want it to look like @AdoraBelle Dearheart's! We seem to have too much current for floaters. I'm going to research the plants y'all talked about above and see if there's something new we can try. But first, we're going to think about how to rescape some and include sand for the cory babies. We're thinking about putting sand in a sort of arc in the front right corner and going most of the way back on that right side because that's where the corys seem to hang a lot. We'll have to move some plants, but that's OK. DH wants to make the big log more vertical, Here's the tank, plus a pic of the corys for tax!

IMG_0593.jpg
IMG_0594.jpg
 
Well, we did it! We rescaped quite a bit and got some Super Naturals Torpedo Beach sand in. Standing the big log up will make the tank easier to clean and give the tetras more racing room. It also seems to show off the anubias better. We also planted an Amazon sword in the back and gave it multiple root tabs. The corys don't seem interested in the sand yet, but maybe they need some time. (Side note, after doing some math, DH thinks most of the gravel in here is at least 30 years old!!) I'll post a picture after the tank has cleared a little better.

Oh, we've figured out that our floating plants are disappearing because the cherry barbs are eating them!
 
Well, this looks so much nicer, IMO. I wish the big log hadn't wound up quite so centered, but after all that work, I'm not moving it again! The corys have deigned to sit on the new sand. If the new plants will take, it will look even nicer. After all that effort, I think it will be months before we try to extend the sand.

.
IMG_0603.jpg
 
Well, we did it! We rescaped quite a bit and got some Super Naturals Torpedo Beach sand in. Standing the big log up will make the tank easier to clean and give the tetras more racing room. It also seems to show off the anubias better. We also planted an Amazon sword in the back and gave it multiple root tabs. The corys don't seem interested in the sand yet, but maybe they need some time. (Side note, after doing some math, DH thinks most of the gravel in here is at least 30 years old!!) I'll post a picture after the tank has cleared a little better.

Oh, we've figured out that our floating plants are disappearing because the cherry barbs are eating them!

Tank looks great! I actually really like the way it looks with the wood in the centre...!

Try target feeding the cories on the sandy area. If these guys have always lived on gravel and were raised on gravel, they might not be used to sand yet, but after feeding them there, they'll get the idea in no time! Like house-training a puppy and getting it used to different surfaces, lol.
 

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