OMG, thank you for sharing this! That's how we can get sand for our Schwartzi corries in our 65 gallon. We've been dreading trying to change out the gravel with all the live plants and fish and such, so we keep putting it off. If we can create a sand beach in the front, where there aren't a lot of plants, I think we can make give our corries a space to do their thing and thus be happier! Yea!
I changed out my 25 gallon tank from gravel to sand last month, I had been reading that it was better for cories and that tank has 5 little green cories. (Other fish are 5 X-ray tetra and about 7 lemon tetra) and I was having a big snail problem. I am lucky that I had a 10 gallon tank not being used so I filled it with water currently being used in the 25 and then added the fish. Put the rest of the water in big buckets. Dumped gravel and live plants, cleaned out all ornaments and left driftwood outside to freeze any live snails.So last month I got 6 pygmy cories to add to my 20gal community tank (relevant threads) with platies, zebra danios, and cherry shrimp. I really loved seeing them school at first. But, I don't think they're doing very well. Of the 6 I bought, 2 were unhealthy and died after a day or two. Another one I later had to euthanize because it was injured to the point that it couldn't swim (I think I might've hurt it while moving decorations around).
Of the 3 I have left (which I'm sure are stressed), one of them (always the biggest) is still healthy, but the other two spend most of their time laying on the substrate, and also seem to be missing the lower fork of their tail fin? I'm not sure if this is from fin-nipping at the store or if my gravel is hurting them. I'm also having difficulties feeding them, since they're so much smaller than the other fish, and don't have safety in numbers to feel safe eating alongside the larger fish.
My intention, at first, was to get more as soon as I can (although I haven't had the money to yet), thinking that once they feel safe in a school they will be more healthy and confident. But I'm starting to feel like the species in general is just too small and fragile to fit in with the rest of my tank. I'm also starting to feel disappointed with the appearance of the fish, although that might just be because I'm not seeing them school anymore.
I'm starting to wonder if I should try to take them back and get another species (like sterbai or julii) instead. When I was initially shopping I felt like these were too big (and still do a little) but I've also realized that they would be juvenile when I bought them, and by the time they were fully grown my platies might also be a lot bigger. I also like the coloration of those species better. My only concern though is that a larger species will leave less room in the tank stocking-wise, as I would also like to eventually add a panda garra at some point and that is also a larger fish.
I'm not sure what route I should choose. On one hand I feel like the sterbai/julii would be safer and more visually appealing in the tank, but on the other hand, I feel like all this might be better if I can just fix the situation with the pygmies, since I didn't feel this way before I was having trouble with them.
Researched sand, bought some set up again. Refilled the tank with water from the bucket (strained with strainer) to about half. Had to let it sit about two days to clear. Then put fish back in their tank strained about another quarter of the water from the previous tank so was 3/4 full. Then added 1/4 of water I had sitting waiting to be put in a tank. I change out 1/4 of water every week anyway. I always have water waiting that has had stability added to it. Denver adds a lot of chemicals to its water.
Fish seem much less stressed and more calm without all the snails. Have had a few but expected that and am staying on top of that issue. Cories like the sand.
But I don’t think I am up to doing my 55 gallon tank, a lot more fish and water. I won’t start a tank with gravel again though.