PlanetCatfish.com

Hello Olga,

Since no one else has replied to your post as yet, let me give it a try. I have not kept C. julii in pH 8.5 water, so I can't speak from direct experience. As you know, higher pH causes ammonium to convert to ammonia, which is toxic to fish. However, my guess is that as long as the tank is mature and the water clean, the C. julii should be OK. They may not readily breed in this water, but survivial should not be a problem.

You could also try adding some peat to your filter, as this will soften the water somewhat.

Finally, you may wish to look at: http://www.planetcatfish.com/cotm/2001-04.htm.

Dinyar

Olga,

Please don't say you're sorry, because if you do, I'll have to feel embarassed for making you feel that way.

I don't know of a simple formula for calibrating the amount of peat to add. I think it will come down to trial and error. Add a fistful. Change the peat after a month or two, and see how much your pH declines. If not by enough, add some more, a little more each time. A target pH of 7.4-7.6 should be fine, I'd think.

Your tetras and gouramis should also appreciate the softer water.

The peat may make your water turn yellow or even brown, like weak tea. Some people like this effect, some don't, but be prepared. Too brown and it will start to affect how much light your plants receive. On the other hand, the peat may slightly raise the CO2 level in your tank water, which could benefit your plants a little.

Good luck,
Dinyar

Olga.

When I first started breeding Cory's I lived in an area where the mains water had readings of between 7.8 and 8.0 pH, the hardness also varied between 15 and 18 GH. I used to store water in a 45 gallon drum and in it I put a pillow case half full of peat moss, this over a week would bring the pH down to around 7.4. and as Dinyar said it would turm the water a golden brown colour, which I thought was great.

The C. trilineatus /C. julii confusion has been brought on by the trade, or more precisly the exporting side of the trade. C. julii usually comand a higher price.

Ian

There is a very positive side to having harder water.. it is easy to manipulate. Bogota tap water is pH 6.8, 3 dGH, and 1kh which is pretty close to rainwater. My problem is that large water changes do not seem to affect the fish at all where as if I had harder, more alkaline water I could set the fish off to spawning by doing a quick water change with rain water or distilled water.
-Shane

Yes, your summary is more or less right, Olga. Your Corys would be happier if you used some peat to lower the pH even if you don't plan on breeding them, but you could probably get away with not using peat and just keeping the water clean.

Dinyar

I am keeping Three Line Cory. In my mind, this species is very easy to keep in various enviroment. But from my experience pH 6-8 is O.K. But if the pH is higher than 8, it will cause them not so comfortable.

By the way, you have not mentioned the temperature. I think there is some correlation between the temperature and pH if you have many plants.