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Blackwater aquascaping with Melanie Holmes, the Queen of Blackwater

Updated: Feb 9

About the Scaper

Born and raised in Wuerzburg Germany, nurse by trade, lover of all things blackwater and botanicals. Having always been drawn to nature style aquariums I find my inspiration not only from research but from hours spent outside. I have truly fallen in love with blackwater / botanical style aquascaping not only for its beauty but also due to its undeniable benefits and the world it creates within.

An aquascape by Melanie Holmes


Blackwater water tanks are nothing short of captivating. Their natural look paired with the tannin filled water make them look like a piece of nature sitting in our home or office. But Melanie and ASG really wanted to push what could be done with a blackwater tank. We were curious on what kinds of plants would thrive in a very low PH blackwater setup, and

Melanie was willing to try with us! She sent us this picture and let us know that most of these blackwater environments are in southeast Asia. In the picture it almost looks like hygrophila corymbosa mixed with some rotala rotunda. Now we could be totally wrong, as we are just speculating, but after some research we found that the origin of both plants were from Asia. So we figured we were on the right track.

Inpiration. An image from south east asia of a natural habitat
Melanie's ASG shipment arrived!

Plant Selection

In an attempt to increase our chances of finding plants that would thrive in a blackwater setup, we sent Melanie a handful of plants, all which are from the southeast Asia area. They were:

  • Bucephalandra pygmaea ‘Bukit Kelam’

  • Crytocoryne wendtii ‘Gree’

  • Hygrophilia corymbosa ‘Siamensis 53B’

  • Rotala rotundifolia

  • Nymphaea Rubra (native to Sri Lanka)

  • Added later, purple bamboo planted in a WabiKusa

A Blackwater Setup According to the Queen

We asked Melanie how she sets these tanks up, and she explained that "I typically don’t use a lot of rock in my blackwater scapes, especially if I'm building a tank for wild type fish ( i.e wild betta or gouramis ) requiring very soft water. I try to imitate a section of a certain habitat ( think ditch , creek , river, etc ) but at the same time not trying to limit myself too much with restrictions of a biotope. Allow yourself artistic freedom to express yourself! I picture a collection of branches, maybe a root pushed against the edges or some rocks and within that tangle you have smaller branches getting caught by the flow of water, leaves and seed pods from the trees above layered within that structure. I picture the sun shining through the branches and detritus, creating shadows and yet allowing enough sun to penetrate to grow plants here and there.

I start with whatever piece of wood inspires me and continue adding sections, branches, twigs until I achieve the overall look - making it appear as if it was on a large piece. I secure everything by gluing all contact points with superglue and setting with an accelerator ( covering the wet glue with sand prior to setting to disguise any residue) Tip - glue black lava rock under or behind the structure to secure it but visually keep it rock free. The next step is just as important, this is where the magic happens! Botanicals! After preparing my botanicals I start adding and layering - again in a way it would naturally occur. This is what will create the most beautiful tannins, giving life to your tank. This is what will allow the growth of microorganisms, supporting life stock in the tank. Before you know it you will see things like Paramesium, cyclops and daphnia scooting around the tank. Success!! I have also jump started this process by seeding my tanks with a culture of paramesium. Due to having very hard tap water I use RO water for my set ups. I added our plants in places I would naturally expect them to be - taller stems along the edges, epiphytes tucked in between wood and rock giving fish a place to hide and again creating a natural flow and feel."

Aquascape by Melanie Holmes

After initial set up expect a rather large tannin burst / release ( even with correct botanical preparation ). Depending on botanicals used, water can turn black with heavy biofilm on the surface and of course biofilm and slime mold growing on wood surfaces. Frequent water changes will help the tank balance but plants are not happy during this time at all as the water becomes very acidic. All plants melted ( I removed the buce to save it ) though the dwarf lillie did surprisingly well and remained largely intact. A few weeks in I was able to add the buce back, started seeing new growth where I planted the crypts. Hygrophila and rotala did not recover. As much as I love the look of plants in my tanks and pushing the boundaries by creating hybrid “planted” blackwater tanks the two are difficult to marry. For my wild gouramis I keep TDS at between 60-80 - plants are not very happy with these parameters. On the other hand I have a tank scaped with elephant skin rock which of course raises TDS. I have found the plants I typically use to do well in a TDS of a minimum of 110 ( ish )

Preparation of the botanicals

ASG was really curious about the botanicals in these blackwater setups. The idea is that in nature, plant matter falls into these streams and rivers releasing tannis which are beneficial to the fish that live in these environments. Melanie told us that...

"I purchase as well as collect my own botanicals. When collecting your own, always make sure you know the area is chemical / pesticide free, make sure your botanicals are dry before use.

I ( try ) to select botanicals according to the scape local I am setting up though it is not always possible - texas live oak leaves are one of my favorites to use because of their size and tropical shape easily blending in with many styles. Do some research, some leaves and botanicals release A LOT of tannins! I always boil any botanical, mainly because I am scaping and want to place them in specific spots. Using them wet allows me to be precise. Many sources suggest letting botanical soak for several days, changing water daily - this will definitely help eliminate some of that initial tannin burst and is considered best practice.

Botanical soaking prior to use
What this looks like in application

Its Scaping Time!

When designing any aquascape, we need to be mindful of composition and form, which could be an article all on its own. We always teach to not rush the design, take breaks, and come back to our designs after sleeping on it for a bit. We will work until we feel as if we’ve contributed as much as we can to the hardscape, and take a break. We keep doing this until we feel as if we’ve creatively gotten out as much as we can from this scape, then move on to planting.

Here is what Melanie had to say about her scaping methods. "I use the same “principles” and teachings of traditional aquascaping when setting up a blackwater scape. I have learned over time not to rush my work. Often walking away for days, moving wood and rocks ever so slightly to create the most natural set up.

Phase1: Hardscape and substrate

Melanie used a sand substrate in the front and aquasoil in the back or areas where planting into substrate. She mentioned that "( Red Flint sand is 100% my preferred sand substrate. It has the perfect texture and beautiful blend of colors ) river rocks and smaller pebbles in the center to build up some height and to use as anchors for the hardscape. ( here is a secret: I actually used three fake rocks with caves in this scape that were gifted to me but you would never know ) I am using dragon wood in this particular setup."

We really appreciated the selection of wood used as it adds dimension to the aquascape with its texture, size, and turns the branches take. When working with our hardscape it's important to remember to work from left to right, front to back, but up and down as well. Keep adding and gluing branches until you have achieved your vision, hardly ever will you find a single piece of wood that’s perfect. When an aquascape looks a little flat, its generally because we haven’t added anything to give it height! Make sure to work in all 3 dimensions.

Melanie also took the time prior to flooding to plant the tank. Make sure to keep your plants wet to avoid them from drying out while you are working. A simple squirt bottle with water in it can help buy you time to plant as you work.

Phase 2: Planting!

And lastly, we flood! One little tip we like to share is to put a plastic bag, or some crumpled up ceran wrap or maybe some dye free paper towels, anything to break the stream of water into the tank to ensure you do not disturb a delicate scape like this. It also prevents the water stream from driving down into the substrate making you water all cloudy. I’ts especially important to be careful with a blackwater scape. Look at this beauty. Melanie is a master at what she does.

Phase 3: Flooding

A little tip from the master... "One tip / thing to consider for blackwater scapes is filtration and flow. I do generally use canister filters but I'm careful to never point the output toward my substrate to ensure my botanical layer does not get disturbed. As a matter of fact most of the time I add a prefilter sponge over the output nozzle to buffer the flow almost completely. In general fish from these regions dislike flow anyway."

Now don't get discouraged if you chose to set up your own blackwater aquascape and it looks like this during the cycling process. The blast of tannis and organic matter from the botanicals we added can cause the water column to get cloudy for a few weeks. This will subside once the tank is finished cycling. Just leave it be and it will pass.

The aquascape cycling. Cloudy water is due to the build up of ammonia.

Maintenance and Feeding

Melanie explains that "Unlike traditional aquariums, blackwater scapes require small water changes ( i perform about 10% every 1-2 weeks ) . I allow botanicals to decompose in the tank and replenish as needed. All part of this style of fish / tank keeping. The incredible benefits and microorganisms created within such an ecosystem make it almost self-sustaining. Feeding prepared foods to livestock is much less needed ( if at all ) in a well established blackwater tank as fish will feed on the seemingly endless supply of microorganisms growing on decaying leaf litter. All beautiful benefits of blackwater / botanical style tanks."

Where is the scape 6 months later?

The scape has matured amazing well due to Melanie's care! The plants that seemed to do the best were the epiphytes. So if you do want to add plants into a blackwater tank from the start, stick with bucephalandra, anubias, maaaaybe a Java fern, and even rosulates like crypts! We had an issue with the stems dying off during the first few weeks due to the explosion of tannis and ammonia. So if you wanted to try and add stems like rotalla and hydrophilia, do so AFTER the tank has cycled and botanicals have balanced out.

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