Substrate

[Jenny]

Hello all! I have a 125 gal tank and my substrate is black sand. I found my love for aquatic plants recently and have around ten plants growing in the sand. I want them to thrive and feel like I would need a better substrate. I’m curious if I could just add Carib sea eco complete to my sand instead of changing out the entire substrate in my established tank? 

[Ken Dyer]

I have a few tanks that have made that transition (adding eco-complete over sand) and for me it has worked out fine. I do find some plants seem to struggle a little to get established compared to a "no sand" tank (dwarf sag) but then take off fine. But as I have never really started two similar tanks and compared against each other it is always hard for me to tell if this is just an observation bias (watched pot never boils) 😉 

The tanks I have taken this route with were sand for a few years so I am hopeful that the sand is full of old food/fish poop to feed the plants. As such I treat the sand layer like a dirt layer in a "dirted tank" and cover it with about an inch or two of eco-complete.

I did see a small ammonia spike with 1 tank, which I assume was disrupting the bacteria on/in the sand when I covered it with eco-complete so do be mindful that regardless of covering the sand or fully replacing it you may disrupt your bacteria in/on the substrate.

As a note: I have also had plants in coarse sand as well, they do take a bit longer to get established but can do OK in a coarse sand so as always I would suggest go with what you think you will like to maintain most. If your plant plans are mostly water column feeders (anubias, java ferns, etc.) then the substrate is less critical and more of an ascetic choice in my mind.

And as always, the worst that is going to happen is you are out some money on substrate, but will have learned how that change works for you, in your tank, with your water and style. That is a lesson that can definitely help you make future decisions 🙂 

[Jenny]

Thank you so much for your input! I really appreciate your time and knowledge. 😊

[Ken Dyer]

You are quite welcome, though not sure I have made it as far as knowledge 😉 Just a lot of learning of what works in my aquariums with my style, The internet would definitely not approve of a lot of what I do, but when the internet's suggestions don't work for me I start trying stuff out and settle on what I get success with 😄 

[tolstoy21]

Unless the sand's composition itself if not amenable to plant roots, you can always try putting root tabs under the rooted plants to feed them and not worry about adding a planted substrate into the tank.  Give that some time and see how that works, and if that's not getting the results you want, then try adding in a different substrate.

If you like the look of black sand, I'm partial to Fluorite Black Sand as my planted substrate of choice.  But it does have some drawbacks, like its hard to get stem plants to stay put in it at first, and its very dusty and needs to be super-washed or else it clouds your tank unbelievably. 

I would imagine that if you want the full benefits of a planted substrate, it's going to have to be mixed into the existing substrate when you add it. 

Edited November 13, 2020 by tolstoy21

[Casual aquatics]

Curious about this as well I have a planted tank that has a wormed dirt and black sand and I have just ordered some Sachem fluoride dark plant substrate to add too it hoping it improves everything! But who knows