20G long "blackwater" planted community after a long hiatus

I have had a fish tank for a good portion of my life, and I've kept just bettas and snails in that time...with a couple of sloppy attempts at java fern and driftwood "aquascaping" here and there. However, my last betta, who I kept in college, went in a very stressful way--he'd lived a long life, but that had left him vulnerable to disease, and one after the other before his passing had thoroughly discouraged me from the hobby. With the lack of space in my college dorm and then apartment, and lingering anxiety about being fit for fishkeeping, I didn't have it in me to start up again until now.

I'm now several years out of college. That time as well as my now reliable income have encouraged me to get back into the hobby again. I've done a lot of research, but I fully expect to hit some roadblocks as I actually put that reading into practice, especially since this will be my first community aquarium. This will also be my first tank above 10 gallons, which is incredibly exciting. A 20 gallon may still be a nano tank, but it's massive to me! I'm hoping this thread can help others in my situation get back into the hobby without so much of the waffling and anxiety I've experienced as I've tried to get started.

And onto the tank! It will be on a heavy-duty steel rack (the Gladiator EZ Connect Steel Heavy Duty 5-Tier Utility Shelving Unit (48-in W x 18-in D x 72-in H), for anyone curious) alongside my roommate's leopard gecko, so I'm waiting to get that rack in before I set it up properly. Which will hopefully be tonight! However, I can at least do an overview of what I've got so far.

Tank Essentials

• Tank: Aqueon 20 gallon long (good size, not too heavy)
• Lid: Aqueon Versa-Top 30" (clean and simple, easy to put lights on)
• Filter 1: AquaClear 50 (saw good recommendations, dedicated area to swap out filter media)
• Filter 2: Hygger Double Sponge filter (M) with a Tetra Whisper 20-40G pump (good reviews and can be used to quickly cycle a hospital tank if need be)
• Additional Filtration: A second bag of AquaClear 50 Biomax to replace the carbon in the AquaClear 50 (carbon will remove the tannins I want!)
• Heater: Eheim Jaeger 100 (good reviews, seems reliable, but I'll be watching it like a hawk)
• Thermometer: JW Aquarium SmartTemp Thermometer (magnets to the side, easy view=check often)
• Light: NICREW SkyLED Plus, 30-36", 30 Watts (good reviews, adjustable intensity, and good strength for the 20G long, though most of it will be blocked by floating plants)

Decorative Elements

• Artificial: A weird cube ("Imagitarium Resin Rustic Cube Aquatic Decor") from PetCo that tickled my fancy. Will probably need some sanding.
• Plants: None (yet! definitely floating plants, and will see if I can't stick to SE Asian, low-light varieties outside of the floaters)
• Driftwood: None (yet! something with tannins and ideally a lot of thin branches to give it a mangrove feel)
• Rock/stone: None (yet! maybe some smooth river pebbles, and possibly a rock "platform" above the sand on one side of the tank)
• Botanicals: None (yet! not sure what will be most consistent as far as producing tannins and reducing pH)
• Substrate: Caribsea Super Naturals Aquarium Sand, 20-Pound, Crystal River (for a natural riverbed look. Inert, I know--I want to see how far I can get with just liquid fertilizer to reduce the cognitive load of the tank)

I'll go into tools, chemicals, etc I'm using as they become more relevant. I want to be thorough! Not much to report on equipment just yet, but I will say that the Aqueon Versa is just a bit off dimension-wise, with it just a smidge too short to sit on the lip of the front and back of the tank. I'll be solving that in a future post, but it seems to be a consistent issue across this current manufacturing run. I'm also displeased with how much give it has when pressing down in the middle, and will probably need to devise something to make sure a cat doesn't try sitting on it for too long, if the light isn't enough! It does look aesthetically very nice and low-key, but I can't say I'm overly pleased with it for the price.

Planned Stocking

• 6-8 Sparkling Gourami (Trichopsis pumila). Seem personable/"present" in their environment, and I adore their croaking sounds.
• 10-12 Kuhli Loaches (Pangio semicincta). Little noodles, and I love their sand-sifting behavior.
• ??? (Snails? Shrimp? Fish? Something else?)

I've been testing my tap water, and it's just under 8dKH at 140ppm, and around 8.4pH. I haven't gotten the GH tested, nor is it available on my city's water report that I can see. This is pretty far from a blackwater environment, obviously, hence the quotations in the title...but I'd still like to get it a little closer. This'll be a planted tank, and I want to try just Thrive liquid fertilizer, which I've heard will lower the pH. I'm hoping a consistent dosing of botanicals will too, and maybe the plants themselves. I've also heard that sometimes, tap water left to sit out can get lower in pH due to whatever additives are in your city's water. If I could get it to 7.8, that'd be great. Otherwise, I'm prepared to investigate some RO options...we'll see. I've seen people keep these fish around 8pH before, but on advice from other users in the forum, I'm going to see what I can do to get in the 7 range.

I have written...a lot, so I think I'll leave it at that, for now. Hoping to post my assembly of the shelf and first thoughts, next. Thank you!

 

Those JW thermometers are great, i have one in every tank. The magnets sometimes are a pain as on occasion, one of my cats decides it is a toy. I would suggest after awhile maybe 2 nerites. If female they may lay eggs everywhere, but they do a great job with algae on my tanks, keeping it quite minimal and they come in quite a variety of patterns on the shells, or at least can, which makes for a bit extra eye candy. Also, dont know if you were able to take advantage, the Aquaclear 50s have been on sale on amazon and petco lately for close to half off, so bonus if you got it!

 

Those JW thermometers are great, i have one in every tank. The magnets sometimes are a pain as on occasion, one of my cats decides it is a toy. I would suggest after awhile maybe 2 nerites. If female they may lay eggs everywhere, but they do a great job with algae on my tanks, keeping it quite minimal and they come in quite a variety of patterns on the shells, or at least can, which makes for a bit extra eye candy. Also, dont know if you were able to take advantage, the Aquaclear 50s have been on sale on amazon and petco lately for close to half off, so bonus if you got it!

Thank you! I had a nerite in the past and I liked him a lot, so I'd be happy to have some again. I'm a little worried the sparkling gourami could nip at their antenna, but I'm not sure how common it is...

And yes, I got it on sale! That and the tank. Very happy about that.

 

Post pics if you can! I love blackwater tanks!!!

 

It sounds like an interesting project, but the KH/pH situation is a bit concerning. With KH8 it will be hard to lower pH without using RO water, and you need to take into account total hardness and TDS/conductivity as well as pH. I don't have as much knowledge or experience with Asian fish as I do with South Americans, so would have to do some research to know what are the best or acceptable parameters for the species you have in mind. With that stocking though, and if water parameters are suitable, I would be tempted to add chili rasboras, I think they look very attractive.

 

It sounds like an interesting project, but the KH/pH situation is a bit concerning. With KH8 it will be hard to lower pH without using RO water, and you need to take into account total hardness and TDS/conductivity as well as pH. I don't have as much knowledge or experience with Asian fish as I do with South Americans, so would have to do some research to know what are the best or acceptable parameters for the species you have in mind. With that stocking though, and if water parameters are suitable, I would be tempted to add chili rasboras, I think they look very attractive.

Yeah, I'm considering cutting with RO. As far as I can tell that would give me the ideal values for the fish. I do know people have successfully kept the fish in harder/~8pH water, but I am looking to try to bring it down. Though it's hard to tell sometimes what the true ideal range is for a fish that's been raised or kept for a long period of time in equally hard water...

Chili rasboras are pretty! I don't think I've seen them in person, but the pictures are very vibrant.

 

Yeah, I'm considering cutting with RO. As far as I can tell that would give me the ideal values for the fish. I do know people have successfully kept the fish in harder/~8pH water, but I am looking to try to bring it down. Though it's hard to tell sometimes what the true ideal range is for a fish that's been raised or kept for a long period of time in equally hard water...

Chili rasboras are pretty! I don't think I've seen them in person, but the pictures are very vibrant.

I think it would be a good idea to use partly RO water if at all feasible.

 

I think it would be a good idea to use partly RO water if at all feasible.

Honestly, the main thing making me nervous is the amount of water it wastes. I could buy a few jugs for water changes every week, but that seems unsustainable for me...but most affordable RO systems have a ratio of like 5:1 wastewater to RO water, it seems like. I was specifically looking at the RO Buddie, since it seems highly recommended as a budget option. I don't have many uses for the wastewater, unfortunately. Not that many plants.

Either way, I'll have just a planted tank for a while before adding livestock. So I plan to see how the water looks in there after a few weeks and then if it's not around 7dKH and 7.8pH (I've heard water hardness can change after a while out of the tap?) I'll see how much RO water I need to cut with, if that seems like an acceptable maximum?

...Would making distilled water at home be insane? I think it's a less wasteful process, and I know that distilled water cut with my tap water can get to a good pH/KH level.

 

A small update: my roommate, who I need to be able to update the shelf, has postponed that a couple of days, so no actual tank setup yet.

In the meantime, I've researched some water solutions if my water parameters don't improve, and have a little experiment running where I put some tap water in a cup to see if it sitting out overnight changes the params at all (simulating the fish tank environment). As far as solutions...distilled is fairly cheap (<$100 and useful, but energy-intensive. Also not a lot of gallons can be stored at once, and a bit slow. Not nearly as wasteful, though. There's also a bulk reef supply RO system for a bit $200 that's 1.5 gallons wastewater:1 gallon RO. There's also the ZeroWater pitcher which is a similar situation as the distilled, but less energy-intensive. And lastly, my LFS sells RO water for .6-.8 cents/gallon, but I'm not sure if I can trust it...

Anyway, we'll see what happens with that tap water.

 

Would collecting rain water be a possibility where you live?

 

Would collecting rain water be a possibility where you live?

It is legal where I am, but I'm a little wary of it. People don't recommend it for drinking. It could be an option to supplement store-bought water, but I'm not sure how I could store it without any nasties getting in/fermenting in the Soup. It gets hot here, and the humidity is great for all kinds of nasty stuff.

Once I get the chance, I'll probably buy a gallon from my LFS and test it.

 

Hey Seren,

If you haven't already done so, you can check out MacZ's article about blackwater basics. It's got some really good info. Maybe there's something in it that can help.

Blackwater: Basics and FAQ

 

Hey Seren,

If you haven't already done so, you can check out MacZ's article about blackwater basics. It's got some really good info. Maybe there's something in it that can help.

Blackwater: Basics and FAQ

Thank you! That's a really great resource. I'll admit I'm a bit wary of attempting full blackwater with the whole water issue...It'd probably be ~5 gallons/week for a water change. Not horrible even if I have to get it from the LFS, but homemade, that's a lot of water waste (7.5 gallons wastewater a week?). Though I guess that's not much more than a longer shower. Something to think about. I'm also a bit nervous from the lack of know-how about true 100% blackwater...it'd be a lot harder to diagnose what's going wrong even with guides like these.

 

I totally understand! After using a lot of Indian almond leaves on a regular basis, I was able to get my ph to about a 7.4 or so. Granted, my normal ph is around 7.8, but the IAL do lower the ph a bit. And I've read a lot about peat moss being really good, too, though I have never tried it. Then there's always leaf litter and drift wood that will leach tons of tannins.

There's really a lot that you can do with botanicals.

 

I totally understand! After using a lot of Indian almond leaves on a regular basis, I was able to get my ph to about a 7.4 or so. Granted, my normal ph is around 7.8, but the IAL do lower the ph a bit. And I've read a lot about peat moss being really good, too, though I have never tried it. Then there's always leaf litter and drift wood that will leach tons of tannins.

There's really a lot that you can do with botanicals.

Wow, not bad at all! I've heard some environmental concerns with peat, though I don't think those apply to peat moss? If I remember correctly, way back when I want to say my pH was in the 7 range once it was in the tank, so should be possible for me too. Thank you! Fingers crossed I can get the shelf assembled tonight and the ball rolling.

 

I have seen discussions about putting peat in with filter media and in mesh bags. I think Fluval has some peat granules, and so does Sera. I would do some extra reading about adding organic peat moss to the tank before I attempted that, lol! That sounds like it could be disastrous if done the wrong way....

Good luck! Post some pics when you have everything set up!

 

Alright!!! I have set up the shelf (finally)! Not the tank, though, because I'm exhausted.


Honestly, it feels very sturdy. I was a little worried, as the shelf doesn't fit the fish tank exactly...but it's a very sturdy feeling particle board. I will be putting a plastic sheet underneath the fish tank to prevent it from getting wet, and probably a towel for wiping up spills around the tank. There IS a cross-beam under the shelf you can't see, and the shelf is rated for 1000 lbs...though the cross beam isn't exactly under the tank's edge. I also situated the tank more towards the back vs the center, so more of its weight would be on the outer metal beams of the shelf than not, and the weight would pull the shelf towards the wall rather than forward. I did put a lot of my weight on the shelf with no issue as far as I could tell, though. I'll be watching it closely, either way, but I'm optimistic.

Onto the more baffling part of this post: the water test! So, these are the results after I let the water sit out overnight...



The KH test (left) turned yellow in 2-3 drops including the first drop, and the gH test (right) turned green in 11 drops total, including the first drop. And then I'd say in person the pH looks to be a 7.7 or so.

Which is...what??? The KH is so low! My utility's website says 140 ppm, but this is saying 2-3dKH? As you can see I did the test 3 times, even once straight from the tap, and all the same. It's really baffling. This is an old home we're renting, so all I can think of is that maybe there's some kind of water softener system or something that we're not aware of? Or that the test kit I got was a dud.

I'm not really sure how to take this, to be honest. These results seem really wacky...2dKH, 11dGH, and a 7.7 pH. With some botanicals, I guess that'd be better for the fish I'm keeping without RO water than what I thought? But I think the GH should be much lower for them, right? And I believe 2dKH is where keeping pH stable gets difficult...gah. Any insight would be appreciated, this was not what I expected at all. Maybe I should get a TDS meter too?

 

Yes a TDS meter would be useful. With the low KH it should theoretically be (slightly) easier to reduce the pH using leaf litter etc. In the end though a low TDS might be more important than a low pH, unless trying to breed specialist blackwater species.

I am also puzzled about such things as I have even lower KH (0-1) and regularly use leaf litter in two of my tanks, but have never really managed to lower the pH, it stays the same as from the tap (6.6-6.8) - assuming the tests are accurate, I believe they are less accurate below KH2. I also have low GH (1-2) and very low TDS. I keep soft water fish and they seem to do well on the whole.

 

Yes a TDS meter would be useful. With the low KH it should theoretically be (slightly) easier to reduce the pH using leaf litter etc. In the end though a low TDS might be more important than a low pH, unless trying to breed specialist blackwater species.

I am also puzzled about such things as I have even lower KH (0-1) and regularly use leaf litter in two of my tanks, but have never really managed to lower the pH, it stays the same as from the tap (6.6-6.8) - assuming the tests are accurate, I believe they are less accurate below KH2. I also have low GH (1-2) and very low TDS. I keep soft water fish and they seem to do well on the whole.

The tap pH at least checks out with what I was getting in a different part of the same city, if I remember right...the high GH definitely concerns me, though. In that case, I don't think cutting with RO would work without making the KH way too low.

 

Why would it matter if KH is 0? Many people use only RO water in blackwater tanks. I believe the humic substances work as a buffer to prevent pH fluctuations. And I have not experienced any issues having a KH of close to 0.

 

Why would it matter if KH is 0? Many people use only RO water in blackwater tanks. I believe the humic substances work as a buffer to prevent pH fluctuations. And I have not experienced any issues having a KH of close to 0.

Ah, I didn't realize the humic substances could prevent pH fluctuations...though this is putting me towards a true blackwater tank. Scary, haha. Do you think those effects would go away if the GH were 5, so cutting with 1/2 RO water?

Sorry for all the questions. As much as I've been researching things, specifics on GH and KH are hard to find, and I don't want to screw up with the fish.

 

Ah, I didn't realize the humic substances could prevent pH fluctuations...though this is putting me towards a true blackwater tank. Scary, haha. Do you think those effects would go away if the GH were 5, so cutting with 1/2 RO water?

Sorry for all the questions. As much as I've been researching things, specifics on GH and KH are hard to find, and I don't want to screw up with the fish.

I think there would not be any problems doing 50% RO.

 

Alright, fish tank is up and running! With a couple of issues...but they should clear themselves up soon.



Here's the hardscape--I'm very happy with it! That's one big chunk of "raw" Malaysian driftwood, and then two smaller pieces of Top Fin Mopani driftwood. Also a couple little hunk of dragon stones ready to help anchor plants down. And then here it was set up with some plants (I'll be getting more in the future and letting these grow before I even think about getting sparkling gourami). Right now, it's a big anubias in the back right, a good chunk of melon sword in the back left, 3 crypts across the front, and 2 chunks of trident java fern across the font. Just what my LFS had, really! I'm hoping that the melon sword will get enough light. I did place it where floating plants won't be established (right in front of the filter outtake), so I think that may be enough. In the end I'm hoping for some valisneria to fill in the empty areas/break sightlines, dwarf hair grass for some visual appeal, and then some frogbit or an equivalent floater all across the top.




And then, uh....




Oh no. Yeah, I thought that driftwood would be okay since it said it was ready to just put in the tank, but it absolutely was not, and floated to the top. Luckily the other pre-treated one (right) was fine, and the left one I did boil to waterlog it and get rid of any possible bacteria since it was a less processed piece of driftwood.

I also messed up a lot of the scape when I was pouring water...getting it into the tank at this height is very difficult for me, so I'm going to pick up a pond pump from Harbor Freight to make it easier in the future, so I don't have to slowly fill the tank with a tupperware container again. It was also enough of a pain I ended up just putting the water conditioner (Seachem Prime) in at the end, so hopefully the plants don't mind that too much.

Lastly, the filter is weirdly loud...it makes this slight grinding noise I can hear from the next room. New out of box, so no clue why. It's not the lid rattling, and I suspect it's the impeller...I might try wrapping something to dampen sound around the base of the filter, or if it really bothers me I'll order a replacement impeller and see if that helps. Kind of a bummer though, quality control would be better you'd think.

On the other hand, this morning, the floating driftwood has gotten a lot better! It's really just one corner that still floats, so I've wedged that next to the biggest piece of driftwood to make sure it takes in water. By tomorrow I should be able to actually fix the scape up.




As you can see, I also went ahead and added a prefilter sponge to my filter, adjusted the heater, and I cut the slots out of the tank lid for the filter + heater instead of just propping it on top of them...I also added Tetra SafeStart and a pump of Thrive to get things going, along with a sprinkle of fish food. I'm not going to worry too much about my water params until things get a little more established. And as for tannins...I may have been a bit too tired yesterday to bother replacing the charcoal in the filter OTL. I'll get those tannins back eventually. See you tomorrow (hopefully!)

 

Driftwood update: Still not sunk It's just one little corner holding out, the rest sinks fine.

 

A bit of a funny story. I boiled it a ton today, no dice. Still floated. So I left it while I went to pick up some (very affordable, thank you local plant man!!!!) plants, and when I got back, I poked at it to remove it so I could get the plants in and...???? It's juuuuust sunk enough that the cube decoration holds it down!

I'll admit, some of these it was very hard to get the roots in the substrate. I couldn't tell where plant ended and roots began sometimes, and i couldnt get ALL of their roots under a lot of the time...so a bit messy. We'll see how well they do. Hopefully I didn't bury any important roots! This is some valisneria (I forgot what kind...might have started with a C? The tall "grass), dwarf sagittaria, and uh. Two other things, and a floater. I forgot what their names were, sorry plant man! They're all sort of "grass" like though. Maybe I overdid it on the grass and should've gotten some more broad-leafed options? Either way, here's the scape for now!




Any critiques? I think as of now it's suitable for the loaches. I'm hoping once this grows out a bit, and the top is covered in floaters, maybe it'll be enough for 6-8 sparkling gourami? Not sure if the coverage will be enough though. Other than that, hopefully it's aesthetically pleasing...I like to think I have a good eye for this kind of thing, but I really struggled with knowing where to put everything!

 

Nice! The two bushy ones at the front are java ferns so should be attached to the wood rather than planted in the substrate (one of them might be its difficult to tell). It should look really good once the plants are established.

 

Nice! The two bushy ones at the front are java ferns so should be attached to the wood rather than planted in the substrate (one of them might be its difficult to tell). It should look really good once the plants are established.

Yup, those aren't planted. The big bushy one just has some of its roots pinned by a rock,and the other is iust kind of wedged into the wood And thank you!

 

Alright! This log is really more for my purposes, since I'm not sure how useful it is to anyone else...but I tested my water today to see what's going on.

pH was a cool 6.5, I'm assuming from my driftwood. So suitable for the fish I want to keep already.

kH was 2-3 again, all the same there.

gH was 7, pretty startlingly lower! I'm not sure if that's because of the plants/driftwood/ferts, maybe because I filled my tank with the spigot outside? That's probably still higher than idel for kuhlis, but it is in the range I've seen people keep them at...and that means less RO water for me.

Then ammonia was .5-1ppm and nitrites 0...didn't bother testing nitrates today because I ran out of test tubes. I'll cool it with the fish food for now, doesn't look like the bacteria are really establishing themselves yet.

I've also ordered some root tabs. I trust plant guy with my life, and he said that just liquid ferts, even with a layer of sand, weren't enough for some swords and vallisneria he had...and my melon sword (submerged in store) seems to be struggling just a smidge.

 

FINALLY got the root tabs in! I've placed a few around those struggling/needy plants I mentioned. Today was water change day, but it was a difficult day, so I'll see if I can't do it in the morning. I got a $15 pond pump to help out.

I also got my TDS meter...168 TDS! Not unexpected, but definitely pretty high. I wonder how much of that is from some loose leaves or even the tannins.

 

I also got my TDS meter...168 TDS! Not unexpected, but definitely pretty high. I wonder how much of that is from some loose leaves or even the tannins.

Maybe a little but I don't think very much in my experience. What does your tap water read? And are you using 50%RO?

 

Maybe a little but I don't think very much in my experience. What does your tap water read? And are you using 50%RO?

Tap is just under 200 TDS. Right now, I'm actually using full tap water. I wanted to see how my parameters looked with just tap in the tank with plants + ferts + etc before cutting with RO.

 

So the tap water has a higher TDS than the tank water, even thought you are using fertilisers? That seems odd.

 

So the tap water has a higher TDS than the tank water, even thought you are using fertilisers? That seems odd.

Yeah, it is...I did top off with distilled water, which could've done it? But the total amount of distilled water I added was less than a gallon.

 

Yeah, it is...I did top off with distilled water, which could've done it? But the total amount of distilled water I added was less than a gallon.

It must have been that though...

 

Yeah, it is...I did top off with distilled water, which could've done it? But the total amount of distilled water I added was less than a gallon.

Fair enough. I won't worry about it too much, I suppose.

Now I just need to wait for it to cycle. OTL. I know cycling is slower at lower pHs but I've been at a little over 1ppm ammonia no matter what for days, haha. I guess I'll just be looking for when the ammonia starts decreasing on its own without water changes.

I'll probably also hit up the LFS for some RO water asap so I can go ahead and get the hardness where I want it. I'll go a little slowly, 25% at the next water change, and depending on how levels look, 50% at the one after that, in order not to disturb plants/bacteria/my pest snails too much.

 

Still no sign of a cycle forming. Even if my end goal is a low pH low hardness tank, should I be raising those in order to cycle? It's consistently at .5-1ppm regardless of whether or not I add fish food after a water change. I do have a population of snails in there.

 

My method of doing literally nothing except for watching the snails bumble around and occasionally tossing some fish food in has succeeded! I've got 0 ammonia. I may stress test before getting any fish, though.

I will say though, I've gotten attached to the snails. Hopefully the water will be hard enough to sustain them at the end of the day. Still haven't gotten the RO water mixture in there, though. That will probably be an experiment for this weekend.

 

I have plenty of snails in very soft water, but their shells go white.

 

I have plenty of snails in very soft water, but their shells go white.

Good to know that they at least won't all die, though that's a shame. Genuinely think my bladder snail's shell is lovely. Has anyone ever tried dosing calcium in soft water? I'm sure it'd help the snails, but I don't know if it'd hurt the loaches or not...though I already have liquid ferts, so there'll be some stuff floating around in the water either way.

 

You’d be better off feeding calcium rich vegetables to help the shells rather than trying to dose the water column.

Also for leaf litter ( you asked higher up ) Indian almond leaves are widely available to buy and do release a lot of tannins. If you’re close to a none polluted area like woodland you can collect your own leaves ( any hard wood leaves, oak is very popular ) although it’s usually better to do this in autumn when they drop them. Magnolia leaves are another great choice as are seed pods and alder cones. I personally like the long and longevity of Jack fruit leaves but they aren’t the cheapest. They may not alter your pH too much but if you do end up cutting with ro and have a kh of 0 then yes they will.