Thanks everyone for the input. I realized I should've specified what type of cichlids from Malawi just as I was reading PlantedRich's post about it. I have 1 male blue haps with 1 female, and 2 male peacock with 2 females. I used to breed Haps way back when, as well as Red Jewels, and got pretty familiar with telling them apart (M/F). I have also kept peacocks before but didn't breed because I didn't have females, not to mention already having 12 tanks running at the time and no room for another (thats a lie, theres always room for another! but the show "hoarders" had just come out and I was trying to avoid an intervention..!) But as far as digging goes, I only really remember the Haps being diggers and the peacocks for the most part were pretty docile by comparison. They spent the majority of the time getting chased by the haps! And with this new tank, theres not a lot of floor space for them to do much digging.
In regards to Lochaber's suggestion about the basket pots, that's actually what I have them in sorta. Its a carrier that the garden centers get their bulk shipments in. This one only holds like 8 pint size pots but its perfect for tthe fish. I just cut the holes a little bigger so the fish can fit through and flipped it upside down. The plants fit nicely and haven't had any pop out yet. I have a picture of the tank on my profiles. I posted a few of my old tanks but that was a few years ago. After college I gave away the majority of them. I was reunited with the 20gal after my friend passed. I also inherited his fish so that's what got me started back up. I've always loved the look of natural plants but I never could get them to survive very long so now that has been my focus. And so far so good! I also got a 5.5gal betta tank that is what I really first started the plants in! And they're doing well too. I should post that one too.
Also, like PlantedRich, I rarely if ever vaccuum my gravel these days, but then again, I don't load up the substrate like I used to. I need to add a bit more soil to the one tank, but I wouldnt attempt to vaccuum it. I keep my eye on the water parameters and adjust as necessary but I usually do a 25% water change once a week anyway, and sometimes more often than that when I want them to breed. Some might say 6 cichlids in a 20 is pushing it, and I typically agree, but for what I'm using the tank for and with the amount of hiding spaces I've made for them, I think its a fair compromise between what I want and what they need. Like I said though, when I see that they're outgrowing the tank or feeling claustrophobic, I'll spring for a bigger tank. How do you guys think I ended up with 12 tanks the first time?!
Thanks again for the replies. Keep em comin!