Platydorus Armatulus and Epsom Salt...?

[hisplaceresort]

Good morning, everyone!
Another salt question.
Epsom salt is a common treatment, along with the antibiotic Metronidazole, for bloat in African Cichlids.
I need to treat my Cichlid tank for bloat, and am wondering how this will affect my striped Raphael catfish. I also have a larger (8") pleco, but I have a tank of Koi I can move him into for awhile if necessary?

Typical treatment is 2 Tablespoons / 10 gallons slowly added over a 5-6 hour period of time, plus the antibiotic. Treatment typically lasts 10 days.

Does anyone think this will be a problem for my catfish?

Thanks!

[Divemaster]

Not a problem at all! I just treated my 75 gallon for ich and an internal parasite and used aquarium salt and API general cure (99% metronidazole) and this is he second time I've done it with my raph in that tank. He takes it just fine and that's what cured his internal parasite a few months ago.

[TwoTankAmin]

There is a big difference between adding salt (NaCl) and Epsom to the water and how it effects conductivity/TDS. Epsom is magnesium, sulfate and oxygen- MgSO4 + 7H2O. Both of the first two can change the hardness of water significantly. Some fish will be fine with this while others will not be. This is the reason for adding it gradually, to prevent osmotic shock. Plecos may not like a sudden jump in TDS. It is likely already living outside its preferred parameters in a rift lake tank and adding Epsom might be too much for it.

In an attempt to avoid having to purchase an ro/di a few unit years back I was using a mix of crushed coral filtered water for calcium addition to which I then added Epsom and a small amount of baking soda The goal was to create the dry season with this mix and then to use my tap as the wet. I would mix about 20 gals. of changing water which came out of my tap at a TDS of about 83 ppm. I was raising the water from there to about 165 ppm. To do this I added 2 tablespoons of Epsom and literally just a pinch of NaHCO3 to achieve this.

One last observation. I was having a forum discussion on another site with a well informed hobbyist about nitrate and fish recently. He mentioned this to me:

Dr. Neale Monks recommends not allowing nitrate to rise above 20 ppm in any aquarium, and to keep it under 10 ppm if at all possible; Neale further writes that cichlids may likely be affected permanently by nitrates of 20 ppm or higher. Over on the cichlid site, Mark Elieson agrees with this, and suggests that nitrates and not diet may well be the cause of Malawi Bloat in rift lake fish.

I am not sure how much I agree with all this this, especially since the measurement scale was not mentioned. Science normally would measure NO3-N using the nitrogen ion scale, but a hobby kit uses the total ion scale. One must adjust between these scales using a factor of 4.4. Either multiply the first or divide the second to convert them. I do know the EPA in the USA limits nitrate in tap water to 10 ppm as nitrogen which is 45 ppm on a hobby kit.

I do not keep rift lake fish, so I am just passing this on for your consideration.

[hisplaceresort]

Great information, TwoTankAmin & Divemaster.
Both answers were relevant, as Aquarium Salt was also part of the recommended bloat treatment. I had asked, and received, answers about regular aquarium salt on a previous post.

In summary; I proceeded with the treatment for 5 days, consisting of the Metronidazole, 2TB/10 gallon ratio Epsom salt, 1TB/10 gallons regular aquarium salt (kept this low specifically for the catfish). 30% water changes daily with the replacement water at the same ratios.

Bloat gone after 3 days; continued treatment for 5. Reduced salt/epsom salt concentrations over the next 3 days with small water changes and then a 50% water change. Tomorrow will be another 50% water change.

Everyone is doing fine, and I noticed no difference in appearance or behavior of any of the catfish during this time.

I have come to a conclusion about Malawi bloat... everyone can get it, even catfish, everything contributes to it, and nothing causes it!

I perform 50% weekly water changes (pretty much the norm for anyone with cichlids, it seems) as this will keep me always below 20ppm and often below 10ppm Nitrate(as measured with an API Nitrate test kit).

It is a balancing act. Rift lake cichlids and platydorus armatulus have very different water parameters in nature. I didn't know it when I bought them; after all, Petco keeps them together! I would use more aquarium salt if it wasn't for the catfish. The catfish have to put up with a much higher pH of 8.2 and gH and kH much higher than what they would encounter in nature, I imagine. But they seem to be tough and are thriving, luckily.

So, in general, what I was told on the forum seems to be holding true; catfish can put up with these abnormal conditions for a short period of time. But again, I do not normally use epsom salt and have reduced my aquarium salt general usage to 20% of what is recommended on the box.

Again, thanks for all the input, it is much appreciated!