Substrate change late in the game

[Another Jake]

Big question about substrate alterations to established tanks...

I have the 20 Long seen below.

pH 7.7ish  |  gH & kH 8-9  |  Ammonia/Nitrite/Nitrate 0/0/10  ...  (This is not perfect for the fish that are here, but they are actually doing great. pH and hardness are high, but straight from the tap and rock steady over time.) Light is a fluval 3 at 50% maximum... which is an overkill light, but hey, I love the thing.

Fish: Ember tetras, Celestials, Albino cardinals, Cherry shrimp, a host of hitchhiker pond snails and a few assassins.

I'd very much like to add a ground cover to the blue section. The plants you see in that area currently are all but dead. The substrate was badly planned. It's very rough and not very deep either. I'm not planning for CO2.

Is it safe to replace that section's substrate with something like eco complete? Will it affect the water conditions? If I get a pH swing or some such thing, it would not do well for the cardinals and shrimp I imagine. Is there a decent alternative cover you'd suggest that won't need me to augment the substrate too much? High maintenance is fine.

 

Side note: All these plants are from here and OMG those Java ferns... They came like that. Those are new. That's how they come. That's two. TWO! Amazing.

Side side note: See any sins here? Anything problematic that you see that I don't would be helpful of course.

[Cory]

I don't think your substrate is the problem. I'd just try different plants, gets some root tabs and experience. Plants grow in all substrates around the world. Most plants can grow even without substrate just floating in water. Outside of compacted sand, substrate is a way to hold plants down and possibly a way to deliver nutrients. Root tabs will deliver nutrients and that gravel will hold it down.