MacZ
- #1
Hello everyone!

This is my 20 Gallon Blackwater setup. I'm not completely new to the hobby, but it has been some time since I had to give up my last tank before this one.
Details (sorry, I'm European, so I can only give most measurements in metric):
Model: Superfish 80 Home (not perfect, but best choice for what I wanted, and I knew I'm gonna mod some things.)
Dimensions: 61cm long x 31cm deep x 45cm high
Filter: AquaFlow 200 (downsized from 300 because the current was too high for the fish even after doubling the length of the spraybar and turning it to lowest flowrate.) with biomedia, filterfloss and sponge. Took out the activated carbon the manufacturer puts in there.
Heater: Eheim Jäger 110watt
Lighting: 14watts LED as was in the set. Mostly set on darkest setting.
Hardscape:
4 pieces of spiderwood, 3 random rocks, common sand as substrate.
Good handful of leaves, half cattappa, half native trees from the backyard.
You can count the fake Vallisneria in the corners as well. As I had to get rid of snails right of the start I'll only get real Vallisneria as soon as my LFS can quarantee there's no more snails in their sales tanks.
Actual plants:
3 pots worth of Anubias var. nana, that have developed really nicely I think.
originally 1 Cryptocoryne, but it didn't do well in the blackwater with the lighting so I gave it to a neighbour in exchange for the tetras.
one pot worth of Dennerle Limnopodium (amazon frogbit), that has already doubled.
Stocking:
- 3 quite old cardinal tetras. Neighbour had them in a far bigger tank for 3 years, but his newly introduced CAE picked them off one by one. Had only 3 out of 10 left, when he gave them to me.
- 5 younger cardinal tetras, likely not wild caught, as one has a slightly deformed spine.
- 5 Otocinclus sp., likely macrospilus, but I'm not quite sure. Glad 5 out of 6 made it to the one month-mark. They mostly go for the omnipresent biofilm and leaf litter, but I also feed them organic cucumber, zucchini, brokkolI and lettuce. I DID NOT put them in to control algae, I think in such a biotope they need to be there and I always liked them. Still, 24h after putting them in there were virtually no algae left and there are still no algae in that tank besides some diatoms here and there. Thankfully most have nice little round bellies, none is overly thin.
Thinking of adding some corys OR 1-2 centerpiece fish in there, but no concrete planning for that yet.
Water perimeters:
Temp: 26°C (78°F)
pH: 6.8
Nitrate: ~20-25 ppm
Nitrite: 0.0 ppm
Ammonium: 0.00ppm
general hardness: 9-10° GH
carbon hardness: 6° KH
chlorines: 0.0
They don't add chlorines to the tap water in Germany, but the piping in the house is at least partially copper, so I use water conditioners (aquatan & aquatan blackwater) with the water changes.
Comments, advice and ideas are very welcome!
So long,
Mac
Edit: It's up and running since Sept 20 this year.

This is my 20 Gallon Blackwater setup. I'm not completely new to the hobby, but it has been some time since I had to give up my last tank before this one.
Details (sorry, I'm European, so I can only give most measurements in metric):
Model: Superfish 80 Home (not perfect, but best choice for what I wanted, and I knew I'm gonna mod some things.)
Dimensions: 61cm long x 31cm deep x 45cm high
Filter: AquaFlow 200 (downsized from 300 because the current was too high for the fish even after doubling the length of the spraybar and turning it to lowest flowrate.) with biomedia, filterfloss and sponge. Took out the activated carbon the manufacturer puts in there.
Heater: Eheim Jäger 110watt
Lighting: 14watts LED as was in the set. Mostly set on darkest setting.
Hardscape:
4 pieces of spiderwood, 3 random rocks, common sand as substrate.
Good handful of leaves, half cattappa, half native trees from the backyard.
You can count the fake Vallisneria in the corners as well. As I had to get rid of snails right of the start I'll only get real Vallisneria as soon as my LFS can quarantee there's no more snails in their sales tanks.
Actual plants:
3 pots worth of Anubias var. nana, that have developed really nicely I think.
originally 1 Cryptocoryne, but it didn't do well in the blackwater with the lighting so I gave it to a neighbour in exchange for the tetras.
one pot worth of Dennerle Limnopodium (amazon frogbit), that has already doubled.
Stocking:
- 3 quite old cardinal tetras. Neighbour had them in a far bigger tank for 3 years, but his newly introduced CAE picked them off one by one. Had only 3 out of 10 left, when he gave them to me.
- 5 younger cardinal tetras, likely not wild caught, as one has a slightly deformed spine.
- 5 Otocinclus sp., likely macrospilus, but I'm not quite sure. Glad 5 out of 6 made it to the one month-mark. They mostly go for the omnipresent biofilm and leaf litter, but I also feed them organic cucumber, zucchini, brokkolI and lettuce. I DID NOT put them in to control algae, I think in such a biotope they need to be there and I always liked them. Still, 24h after putting them in there were virtually no algae left and there are still no algae in that tank besides some diatoms here and there. Thankfully most have nice little round bellies, none is overly thin.
Thinking of adding some corys OR 1-2 centerpiece fish in there, but no concrete planning for that yet.
Water perimeters:
Temp: 26°C (78°F)
pH: 6.8
Nitrate: ~20-25 ppm
Nitrite: 0.0 ppm
Ammonium: 0.00ppm
general hardness: 9-10° GH
carbon hardness: 6° KH
chlorines: 0.0
They don't add chlorines to the tap water in Germany, but the piping in the house is at least partially copper, so I use water conditioners (aquatan & aquatan blackwater) with the water changes.
Comments, advice and ideas are very welcome!
So long,
Mac
Edit: It's up and running since Sept 20 this year.