blackwater a good idea or no?

[meadeam]

I really like the look of blackwater, and understand that it does have some benefits.  I've been considering adding catapa leaves to my 36g bowfront which is home to black mollies, harlequin rasbora, black neon tetras, cories, and a bn pleco.  I also have (too many) mystery snails, and a breeding colony of neocaridinia.  Substrate is sand, with bagged aquasoil underneath.  I have several pieces of driftwood, and the tank is moderate to heavily planted.  pH is 6.4.  Water is very hard according to the Coop test strips, with very low buffer.  I'll do some research of my own, but I'm wondering what adding the leaves will do to my parameters, and if everyone will be happy.

[meadeam]

well, seems like black water might be a no-go for the black mollies.  Let me know if you've found otherwise.

[Anjum]

As you've found, your mollies want somewhat different parameters. But if they seem to be doing ok, then it's not much to worry about. You could add crushed coral, either to your substrate or to your filter media, to add some KH (buffer). And that will probably raise your pH somewhat, which will be more stable for all inhabitants in your tank (particularly the shrimp & snails). I think if you have sufficient buffer, you can add some catappa leaves for their tannins. In general, botanicals will slowly lower pH, but keeping stable KH in the water will keep it from crashing. 

[meadeam]

Interesting.  I may experiment with crushed coral a bit. 

[TeeJay]

I agree with @Anjum. I think with the pH you have and low kh I would supplement some crushed coral. I have high gh but no kh out of the tap so I put cc in my hob as well as one mixed in the substrate. Takes me from a 0 to about a 4-5. When you put it in the hob it usually dissolves quicker to help get the kh u "quicker'. But it's a gradual increase. Maybe putting it in the hob is better if you have your substrate set up how you like. You could just sprinkle around a bit on top of the substrate like small accent rocks. But definitely getting a better buffer would possibly allow you to add the catappa leaves.

[Gannon]

With mollies no, but it is a very fun style of tank to try with the right fish!

[CrashBandit05]

Just my experience so take it as .02!

I got a surprise black balloon Molly fry (under 1/2 inch)when I purchased my clown pleco and some pieces of driftwood. Now that it's the size of my smallest candy cane tetra, it schools with them and eats very well!

I have a 29 gallon blackwater set up with >7ph and temperatures around 80-82. The little guy/gal really holds it's own with the other fish and the tank boss german blue ram. 

[meadeam]

I may slowly change my parameters and see how it goes.  I have such low buffer out of the tap, and fairly low pH.  I think I will add some buffer with the crushed coral, and thus a bit of pH (currently at 6.4 so I have a bit of room).  I need to keep gH from climbing much higher though, it is already on the 'very hard' end of the scale.   For some reason mollies have not done great in my tanks.  I've lost quite a few to unknown causes.  I have tetras, rasbora, cories, and a bn pleco who are all a couple years old and doing well.   

[meadeam]

I got the pH and KH up in my tank, and now it is on the hard/high side for everybody but the mollies and snails.  I decided to move out the rest of the inhabitants, and I rather impulse bought a 20 long and Oase BioPlus 100 filter for a kitchen island mini-peninsula blackwater. I don't know if it will be a true blackwater in the strict sense, but I'm going to shoot for something more hospitable for tetras, cories, rasbora, and pleco. I bought some inert substrate, a bunch of botanicals, and I have some driftwood to add.  I'll order some low light plants, or steal a few from another tank.  New setup, yay.

[nabokovfan87]

On 9/12/2022 at 11:30 AM, meadeam said:

I really like the look of blackwater, and understand that it does have some benefits.  I've been considering adding catapa leaves to my 36g bowfront which is home to black mollies, harlequin rasbora, black neon tetras, cories, and a bn pleco.  I also have (too many) mystery snails, and a breeding colony of neocaridinia.  Substrate is sand, with bagged aquasoil underneath.  I have several pieces of driftwood, and the tank is moderate to heavily planted.  pH is 6.4.  Water is very hard according to the Coop test strips, with very low buffer.  I'll do some research of my own, but I'm wondering what adding the leaves will do to my parameters, and if everyone will be happy.

I tried IAL / Catapa leaves for the first time recently and I was pretty surprised at how it ended up.  Let me elaborate a bit and then hopefully that provides the context for what you're targeting.

My tank has generally always had some wood in the tank. This is where the majority of the tannins come from and it's the place where I find it to be the easiest method for tannins to develop for a basic "look".  This will alter PH slightly, but if you're doing regular water changes you're talking about a very minor amount.  If you're literally stacking the tank with a pile of wood, at that point you'd have enough surface area to cause some changes. When I did the leaves my hope was to add to this look.  It's a pretty bare tank and so blackwater was the look for it, for me.  I added just about the entire pack of leaves and within about 3-4 days the leaves were halway gone.  I added more, moved them to places where they weren't in flow and the fish and shrimp could interact with them a bit more. If you have something like hardscape and you can wedge a leaf in there, or a kelp holder, that might be a great way to add leaves without having it on the substrate.  Obviously, if you're going for a full blackwater, filter allowing, you would just add those leaves in without worry.   I would highly suggest something like cones, pods, etc. in addition to wood to give you that blackwater look.  If you're trying to rely on JUST leaves, I think you're talking about a lot more leaves than makes sense to get the water to shade. 

Rooibos tea is also a great option, as long as it's pure / organic. 

As for the fish in question!   I think most nano fish, corydoras, plecos, will do well with the blackwater setup.  It shades out light and that's what they tend to want. Corydoras and plecos especially fall into that category.

from another forum, trying to google search some info about the point that you mentioned.
 

Quote

Mollies in a black water environment will develop "shimmies" and will gradually get worse over time. As Lupin said, the acidic, low TDS environment will cause them to go downhill fast.

That being said. I don't know what is meant by "acidis, low TDS" environment.  Potentially an acidic, high TDS environment is fine?  Are they viewing 7 as normal and 7.4 as the target?  I'm not quite sure.

Looking online I'm seeing:

Acidity: 6.7-8.5 pH For me, that means "optimal" is about 7.4-7.6.  They like hardwater, some salt in the water, generally speaking. https://www.aquariumcoop.com/blogs/aquarium/molly-fish-care   Quote Do mollies need salt in their water? Many fancy mollies are bred in overseas locations where salt water is cheaper than fresh drinking water. Therefore, the fish farms often raise them in brackish water that has both high pH and GH (or water hardness). When these brackish-bred mollies are transported to wholesalers, fish stores, and home aquariums that use fully freshwater setups, the change in water parameters can cause their kidneys to shut down. If you have naturally hard tap water, your mollies may not have any problems, but if you have soft tap water that lacks minerals, they may develop diseases like ich (white spot disease), fungus, and livebearer disease. For people with soft tap water, we suggest adding Wonder Shells or Seachem Equilibrium to increase the amount of calcium, magnesium, and other beneficial minerals in the fish tank.

Edited October 12, 2022 by nabokovfan87

[meadeam]

My main planted tank is a slightly alkaline at 7.4-7.6 when the C02 is off, and TDS gets up to >300 between water changes (my tap is around 185).  This is with the addition of crushed coral in the filter, and wondershell in the tank.  It is definitely in range for the Mollies and Snails.   I was losing mollies for no apparent reason several months ago, so hopefully that is under control. 

 It isn't totally off the scale for the Amazonian nano fish in the tank, but definitely not ideal.  If the new blackwater, or Amazon setup can get just under my tap values in terms of pH and hardness, I'll be happy with that and hopefully the fish will be too.   I'm looking into bottled products as well as botanicals.    I think it will be fun to have a couple tanks that are going in different directions water-wise.   I like that part of the hobby.