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lowering pH/ blackwater tank conversion

7K views 14 replies 7 participants last post by  candymancan 
#1 ·
Hi,
So I'm considering converting my fully planted 40g breeder to a blackwater tank by filtering through peat in an effort to lower my pH. has anyone tried this? tank inhabitants include female bettas, a bristlenose pleco, glowlight tetras, black neon tetras, and a bolivian ram. my water is already super soft (KH at about 2dGH and GH around 5dGH) but my pH is around 7.5-7.8 (depending on the time of day). I am really looking for a way to get the pH down a bit for them but am unsure what to use that will remain stable. is peat the right solution?
 
#2 ·
The right solution depends on what you see as right. Peat is falling out of favor with aquarists because it's a non-renewable resource. Not to mention in my experience you can never buy just a little. Indian Almond Leaf (IAL) is very much the favored substance now to lower pH. You might also try adding some large piece of malaysian driftwood. I have a couple of pieces in my tanks, and it lowers the pH down to about 7.0 from 7.8. Fallen oak leaves are another thing I use to stain my water and lower my pH. I collect them from the ground in the fall and store them year-round. But you have to make sure you know what an oak leaf looks like. If you don't want them littering the floor of your aquarium, then you could put them in a bag in your filter.

With a KH of about 2, you should be able to move your pH pretty far down. No matter what you use, you'll need to replenish it from time to time as tannins are removed when you do water changes.
 
#3 ·
Mind if I ask why you're wishing to convert to blackwater? I only ask because it is possible that trying to change could cause more harm than good. If you've had the fish for a while and they are fine then I see no reason to try and drop the pH. A stable one would be best.

I'd avoid the peat in your filter since you already have fish. With your low KH, using that method is very liable to lower your pH too much too quickly and cause pH shock for the fish. This is the same reason I'd argue against boiling leaves to make a blackwater extract.

Driftwood, leaves (oak, beech, Indian almond), or possibly alder cones would be better options in my opinion. If you go those routes I would still go slowly just to be on the safe side. Say add an IAL, let it go for a few days, test, and then proceed. I did a lot of experimenting to see just how much of everything to add to get the color I wanted. That was before I had fish.

One thing I don't have any idea about is how much (if at all) tannins impact light penetration. My blackwater tank is the same size as your tank, but I don't have any plants, so can't say if they would suffer because of possibly less light.
 
#4 ·
Hi,
So I'm considering converting my fully planted 40g breeder to a blackwater tank by filtering through peat in an effort to lower my pH. has anyone tried this? tank inhabitants include female bettas, a bristlenose pleco, glowlight tetras, black neon tetras, and a bolivian ram. my water is already super soft (KH at about 2dGH and GH around 5dGH) but my pH is around 7.5-7.8 (depending on the time of day). I am really looking for a way to get the pH down a bit for them but am unsure what to use that will remain stable. is peat the right solution?

IMHO no need to lower the pH.

In your tank (as in mine) you have a planted tank with high ph and low kH,

Therefore you pH is "high" only because the plants of sucked out the carbon dioxide. Which can hardly be harmeful to any fish. I routinely have fish supposidly "needing" a low pH live for years an years in my tank which have a ph of 8.4-8.8 (api high range test kit) due to the plant action.

I also use peat moss in the substrate and that does have an immediate effect of creating a low ph. But that lasts for only a day at most. Once the plants condition the tank the pH rises.

What does happen in the KH and GH stay at low values but with just a sand substrate both KH and gh rise over years to very high values. But neon tetras do much better with the peat moss in the substrate.


my .02
 
#5 ·
thank you everyone for your valuable input. I do already have 3 small to medium pieces of Malaysian driftwood in the tank but they haven't influenced the pH at all that I have noticed. they also don't seem to release many tannins either. I have been playing with the idea of lowering my pH since I set up the tank in February but wanted to make sure I would have the ability to keep it stable as this is my first tank and I have heard scary things about pH buffers. my low KH made me worried that anything I added would drop it too much.

as for why a blackwater tank and peat...I actually just discovered it on a thread while searching around the forum and was fascinated. I didn't know if peat or almond or oak leaves were safer methods as they were natural or if I should make any changes at all. this thread is about possibilities and keeping my fish happy:)
 
#6 · (Edited)
Can you take a picture of your small/medium driftwood ? I have a 27g Hexagon has a pretty large piece of driftwood in it.. Its a U shape and its about 15-17 inches tall and its almost as wide as my tank and my tank is 20 inches wide (its not very wide its a hexagon remember lol ).. My PH is 6.8-7.0 and my tap water is 7.8. My other tank with no driftwood the ph is 7.6.. Just to give you an idea, that driftwood does lower PH.. You need a large piece though.. using small pieces wont do anything. And its a slow process you aren't going to see results in a few days

 
#7 ·
Welcome to TFK! Always good to find people who do the research beforehand! Especially with the more sensitive fish. . .

Bolivian Rams aren't fans of things like shifts in parameters, it takes them a while to get used to changes, so if you do decide to lower the Ph, do it slowly and keep a close eye on them. Your Ph is a *little* on the high side, but the Kh is perfect for them, and in my understanding, that's what matters the most. If the fish seem well with the Ph as it is, I'd be leery of changing it on them for such a slight amount. . .

I think the amber water is beautiful, and my fish really seem to enjoy the dim environment. It doesn't take very many Indian Almond leaves to bring my 55g to a color we're all happy with. I've had a shoal of BR for well over a year now, and I use Indian Almond leaves in their tank, but never enough to shift the Ph enough to register on the API kit - my Kh is 3gtts, so should drop easily. I doubt my water is as dark as BWG's blackwater tank, but if the effect is what you're after, you *might* be able to get it without too much change in Ph. I did a series of bucket tests before adding leaves to the main tank, so I knew what to expect before putting the IAL in with the fish.

I have driftwood, too - not all driftwood is created equal! Softer woods will release more tannins initially than hardwood. It also depends on how long it's been in water, or if it was boiled before putting it in the tank. Same goes for leaves - they'll need to be replaced every few weeks if you're using them to maintain a specific Ph. Another good bucket test, and something that you'll have to keep a close eye on!

Good luck figuring out what to do! I hope you plan to share pictures of your setup with us? I'd love to see it. I'm a huge BR fan! ^.^
 
#8 ·
I will post pics of the driftwood and Bolivian Ram when the lights come on for the day (soon) :) and will check the pH again (maybe I've been testing too late in the day to even notice the driftwood lowering it?) I also like the appearance of tinted water which is why I was curious... all three pieces of driftwood have been in there for at least a month, the largest one was added in February after 2 weeks of soaking (lots of tannins then) and the other 2 were added later from my lfs who had them in tanks already

I love your piece of driftwood candymancan! the snails are beautiful too, I wish I could keep them but my water is too soft for even pond snails to properly develop shells...
 
#9 ·
ok, so I tested my pH this morning after the lights had been on for 2 hours and it was 6.6 so apparently the driftwood has been working its magic now that I have more pieces and its been (much) longer than I thought in between tests (whoops!)

now I'm getting worried that it might drop too much...is this a valid concern? should I think about adding a buffer? and would it even be safe to add something to tint the water a little or is not worth it? thanks for putting up with my newbie questions/ concerns!
 

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#10 ·
You shouldn't need to worry about buffering the water. My water is softer than your's and I rise my GH to where your's is, but do nothing for the KH. You can add a few leaves if you want the look, but honestly your tank looks pretty sweet! lol Just noticed the random car ornament in a tank that looks so natural.
 
#11 ·
thanks! the car model was my boyfriend's idea, he did a great job making it look rusty and natural-ish and the fish love it :) so it's ok by me. I'm not sure about tinting the water yet...just a thought...a possibility (the same as a future potential sand swap as I'm bummed about the waste of money on the eco complete)
 
#15 ·
Yea I like that car lol..

As for buffering the PH you can put small pieces of coral rock in there bout the size of your car.. Or damn I forgot the name of the rock but its a really bright white rock.. If you go back a page and look at my picture of my tank.. You see that white rock holding my driftwood up.. I have that in there to buffer my PH.. as my tap water PH is 7.8, my driftwood lowers it to like 6.8 but with my snails I don't want their shells to erode.. That rocks puts the PH at an even 7.2
 
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