Who Gives A Fish Forums

I'm using an under gravel filter, as I mentioned earlier, and it's got factory slits on the filter plate - the substrate needs to be coarse enough not to pass through those slits, that's my main consideration here.

So I dug up a definition of sand from Wikipedia - it seems like sand particles range from 0.0625 mm to 2 mm in diameter. Anything within that range is considered a sand grain. It's interesting to note that sand falls between gravel (which starts at 2 mm) and silt (which is smaller than 0.0625 mm).

My previous substrate, which I used for the past 12 years, had grains smaller than 1 mm.

coltin wrote: ↑Fri Dec 20, 2024 4:56 pm When it comes to South American cichlids, I've learned it's generally better to stick with just one species of bottom dweller per tank, unless you're working with a massive tank - we're talking way bigger than my 55 gallon.

I'm listening, but I'm still stuck with the substrate issue, and my main concern is compatibility with the Geophagus and the Cory's, I just don't want to give up on the idea of having them in the tank, and I'm not convinced that the substrate I'm using is a deal-breaker.

Geophagus are lovely fish if you decide to go for them, I've got two altifrons and I'm thinking of getting a couple more, they're really coming into their own now they're maturing, stunning to watch.

To me, sand is something that's got a very natural look and feel to it, like this Wio Heaven sand. I've seen some great examples online, and they've all got a varied grain size. I know you're using an under gravel filter, which isn't ideal for sand, but to be honest, gravel isn't really compatible with Geophagus either - they're a sand-sifting species, after all.

I usually just try to give you the information you need to make a decision, but in this case, I think you really need to decide whether you want to use gravel and an under gravel filter, or go for Geophagus and other sand-sifting species. I understand your concerns about bacteria issues in sand, but if that's a deal-breaker for you, then I'd say it's best to avoid keeping Geophagus.

If you do decide to go with a gravel bottom tank and want to keep cichlids, I'd recommend Festivums or a Laetacara species. Festivums are great because they stay in the upper third of the tank, and they're not tall-bodied like Angels. Laetacaras are also a good choice - they don't dig excessively and tend to stay in the bottom third of the tank, but they're not exclusively substrate-dwellers like some other cichlids. I used to keep a group of L.Thayeri, and they'd spend most of their time around the wood and rocks in the top of the bottom third of the tank.