"Blackwater" aquariums

[Scaperoot]

I've been contemplating rescaping one of my tanks and the idea of having a "blackwater" tank is really intriguing. I found this great article as I'm trying to learn as much as I can about what a blackwater tank is: Does your "blackwater aquarium" truly contain "blackwater?" A "case st - Tannin Aquatics

So admittedly, it's the aesthetic that I'm drawn to. I have a question regarding water hardness and the fish I can add to the aquarium. Once you've begun adding the things you need to release tannins (botanicals, peat moss, etc), what should you expect to see happen as far as PH? I haven't tested my tap's PH lately but let's say it's in the 7.8-8.0 range, what will that drop to eventually? Second question is, which nano fish thrive in this environment? I would love to have a school of Neon Tetras in this tank. Another question would be, what are some things I can do to maintain the PH if my tap is considerably higher than what the aquarium runs at? I'm ignorant (for now) to this setup, so any suggestions are appreciated. 

This looks amazing to me.

Edited August 8 by Scaperoot

[NOLANANO]

I don't really know all the answers but one time I put leaf litter in my 75G and then didn't do a water change for a few months and my PH dropped to like 6.0 from about 7.5 out of the tap. The water was also much softer and all my shrimp died.  I was experimenting with a no water change idea but it was an epic failure.

[redmare]

I want to follow along because I also love the black water look! I don’t know a ton about it, but I think the best option for your tap water being way different is to do more frequent, much smaller water changes. If you’re only changing 10-15%, you won’t be greatly affecting the pH. 

[Scaperoot]

I'm realizing now that it's best for me to stick to higher PH setups. I'm not giving up keeping shrimp just for this look. Not worth it for me. Maybe some day. 

[AllFishNoBrakes]

Yo! I have a couple Blackwater tanks that I’ve been running for about a year and a half each. I’ll do my best to explain what I’ve done, and what I’ve noticed with my personal experience. 
 

First here’s the tanks:

20 Long with Chili Rasboras, Green Neon Tetras, CPO’s, Shrimp, and Ramshorn snails. Spiderwood, Cholla wood, and several varieties of Anubias. 

29 gallon with Albino Cory’s, a couple remaining Glowlight Tetras, Wild Caught Black Neon Tetras, tons of shrimp, and a few snails. Spiderwood, Anubias, Java Fern, Amazon Swords, PSO, Crinum Calamistratum, and co2. 
 

Both have been up and running for about a year and a half. Started with the 20 long, and loved it so much I did the same to the 29. 
 

On 8/8/2024 at 6:21 AM, Scaperoot said:

Once you've begun adding the things you need to release tannins (botanicals, peat moss, etc), what should you expect to see happen as far as PH?

Let me start with my water from the tap is naturally on the softer side, with already lower ph, and very little buffer. I expected the tannins to deplete the KH and massive sink my ph, but that hasn’t been the case at all. These blackwater tanks actually run higher in gh and kh than my non-blackwater tanks, and the ph basically hasn’t shifted at all. I was very surprised by this, but every time I test parameters I’m getting the same results. I think it’s because I still water change once per week, and there’s less plants than other tanks, so less things get scrubbed from the water column. Again, I expected these tanks to burn through KH and run super acidic, but that hasn’t been my personal experience. 
 

On 8/8/2024 at 6:21 AM, Scaperoot said:

Second question is, which nano fish thrive in this environment? I would love to have a school of Neon Tetras in this tank.

Any fish that come from a blackwater environment thrive and look great. My Chili’s, Green Neons, Black Neons, and Glowlight Tetras really POP against the blackwater and darker environment. Neon Tetras would look incredible, too. 
 

On 8/8/2024 at 6:21 AM, Scaperoot said:

Another question would be, what are some things I can do to maintain the PH if my tap is considerably higher than what the aquarium runs at?

Again, my experience has been to treat these tanks like all my other tanks in that they get consistent water changes weekly. I simply rotate adding additional botanicals every other week. I water change every week, and then week 1 I’ll either throw some botanicals in or boil them and then chuck them in. Week 2 I’ll probably add a little tannin tea that I made from boiling the botanicals. Week 3 we’ll replace the leaves and save the tea. Week 4 I add tea. Rinse and repeat. Again, my parameters have remained consistent with this method. 
 

Feel free to message me or respond here if you wanna continue to chat about my experience. I’d never push you to make a decision, but I’m always happy to share my personal experience. Blackwater has been a lot of fun, and I love the aesthetic. I don’t see me stopping anytime soon. 

Edited August 8 by AllFishNoBrakes

[Scaperoot]

So your cherry shrimp are doing fine? That was my main concern. I usually plant heavy, but I'd cut back if I could set this up. I'd still have a few crypts and anubias. How many gallons are you removing each week? The tank I'm rescaping is a 20 long, so this is perfect. 

[AllFishNoBrakes]

On 8/8/2024 at 12:07 PM, Scaperoot said:

 

So your cherry shrimp are doing fine? That was my main concern.

 

Before this was a Blackwater tank, it was a shrimp only tank for about 2.5 years. I pulled about half of them out, and left the other half in. Nothing happened. They’re chillin. They were the OG “canaries in the well” and I’ve seen no difference. Same with the 29 gallon. Let me see if I can find a pic during feeding time:

Shrimp are still crushing. Keep in mind, my water is already naturally softer, with very little buffer, and lower ph. 
 

On 8/8/2024 at 12:07 PM, Scaperoot said:

How many gallons are you removing each week?

2 gallon each week on the 20. 5 gallons each week on the 29. 

[NOLANANO]

On 8/8/2024 at 1:07 PM, Scaperoot said:

So your cherry shrimp are doing fine? That was my main concern. I usually plant heavy, but I'd cut back if I could set this up. I'd still have a few crypts and anubias. How many gallons are you removing each week? The tank I'm rescaping is a 20 long, so this is perfect. 

I think my issue with my shrimp was not changing the water for so long. They had issues molting. If you do regular water changes, I think you'd be fine.

[Kurt Brutting]

@AllFishNoBrakes beautiful black water scapes! Great job!

[johnnyxxl]

On 8/8/2024 at 8:21 AM, Scaperoot said:

I've been contemplating rescaping one of my tanks and the idea of having a "blackwater" tank is really intriguing. I found this great article as I'm trying to learn as much as I can about what a blackwater tank is: Does your "blackwater aquarium" truly contain "blackwater?" A "case st - Tannin Aquatics

So admittedly, it's the aesthetic that I'm drawn to. I have a question regarding water hardness and the fish I can add to the aquarium. Once you've begun adding the things you need to release tannins (botanicals, peat moss, etc), what should you expect to see happen as far as PH? I haven't tested my tap's PH lately but let's say it's in the 7.8-8.0 range, what will that drop to eventually? Second question is, which nano fish thrive in this environment? I would love to have a school of Neon Tetras in this tank. Another question would be, what are some things I can do to maintain the PH if my tap is considerably higher than what the aquarium runs at? I'm ignorant (for now) to this setup, so any suggestions are appreciated. 

This looks amazing to me.

I have a black water tank.  My pH slowly drops but the fish I have want acidic soft water in nature.  My tap water is softer to begin with.  My signature has some nice videos of my tank and it's current look.