Recent discus purchase

[Wrencher_Scott]

On 2/25/2022 at 9:14 AM, Odd Duck said:

Do you know if studies have been done in other species from the same waters as angels and discus?  Seems like they may also be adapted to pull minerals out of their very soft, mineral deficient, native waters.

I would say any "black water" fish has the ability to do this, that's how they survive in those waters. To us fish keepers I would say it is more important to realize they do NOT have to be kept in these low mineral, low pH waters.  

 

[Odd Duck]

On 2/25/2022 at 12:51 PM, Wrencher_Scott said:

I would say any "black water" fish has the ability to do this, that's how they survive in those waters. To us fish keepers I would say it is more important to realize they do NOT have to be kept in these low mineral, low pH waters.  

 

That may not be the case.  Different species may react quite differently.  Rabbits are able to absorb calcium from their food extremely well, much better than many other species of herbivore and far better than many other species of mammals.  So you could have fish that absorb minerals from their food more efficiently living right alongside fish that can absorb minerals through their gills efficiently but both happily living in the same, mineral deficient water.  I’m very aware of adaptability, but it takes different forms in different species.

[Patrick_G]

On 2/25/2022 at 12:25 PM, Odd Duck said:

That may not be the case.  Different species may react quite differently.

Yes, here’s some quotes from the paper I linked. The first mentions the difference between characids and the studied cichlids. The second mentions the difference between Angels and Discus. It’s geeky by very interesting. 

Overall, there appeared to be high sensitivity to inhibition by low pH, yet low intrinsic branchial permeability limiting diffusive ion effluxes, resulting in relatively low net loss rates of Na⁺, the same strategy as seen previously in other blackwater cichlids, and very different from the strategy of blackwater characids. At low pH, Na⁺ uptake in angelfish was inhibited competitively (increased Km = 166 μmol L^− 1) and non-competitively (decreased J_max = 106 nmol g^− 1 h^− 1), whereas in discus, only a decrease in J_max (112 nmol g^− 1 h^− 1) was statistically significant. 
 

Discus fish were more tolerant to low pH than angelfish, as seen by lesser effects of exposure to pH 3.6 on unidirectional Na⁺ uptake and efflux rates and net Na⁺ and Cl⁻ loss rates. Overall, discus are better than angelfish in maintaining ionic balance under acidic, ion-poor conditions.
 

 

[Stephen Zawacki]

So the uvc in line is also a fluval product, it goes in the output line on the canister filter so the water has to go through it, it is one of the best purchases I have every made reccomend for sure 

[Andy's Fish Den]

On 2/25/2022 at 12:06 PM, Stephen Zawacki said:

What is the sweet spot for the temp for them I'm getting conflicting info, so people are telling me 88 to 89, then so people are saying 80 degrees, is around the middle 83, 84 good ? 

I keep my discus tanks in the 83-86F range. I've found over the years that my wilds can tolerate a wider temp range, they've been down to as low as 78 when I had a power outage, and up to 90. The domestic strains I've kept have been more sensitive to temp swings, I had a tank of pigeon bloods become lethargic and not wanting to eat when they got down below 80. 

My discus I have now are kept in my tap water, which is well water, pH runs 7.4-7.8 and my GH and KH both run right about 150. If I decide I want to breed them, I will use RO water that is reminerslized to correct parameters. 

As far as plants, plant the tank to suit you. My two tanks I have now with discus both are planted, one heavily, the other with just four swordplants and couple crypts. Some species of plants can't tolerate the higher temps of a discus tank, but I've found most swords, crypts and val plants do good. As long as you keep on top of your water changes, once a week or so, and trim plant leaves that are dying so that they don't rot in the tank to pollute the water, it is very doable to have a planted discus tank. If you do ever want to use salt, it will harm the plants, so you'll have to either remove the fish to a hospital tank, or remove the plants. 

Edited February 26, 2022 by Andy's Fish Den