Hi all. This is my first post, so please correct me if it is in the wrong spot, etc.
I had 6 red albino guppies and one set of fry (about 13.) 3 adult male, 3 adult female. One morning I woke up and one male was dead. Hm, well, ok, I checked water parameters, and everything was ok except pH (more on that later), but couldn't figure out a cause. Didn't worry too much.
Next day, one of the other males started acting odd- hanging out at the bottom, hanging face down into plants, hiding in weird cramped spots. I kept an eye on him, but didn't know what to do. Then the third male showed the same signs! Lo and behold, they both died (so this is about 4 days after the first male.)
Now one of the adult females is also showing signs- floating sideways mostly. She can right herself for a while, but it's like it tires her out. And she won't bother swimming away from my hand if it gets near (obviously I don't do that much, I don't want to add stress.)
The fry have showed very few signs. I had two die this morning, but they are fragile in general, right? So again, not sure that's something to worry about. I've treated ich in a different tank in the past, and no signs of that. I suspect something is wrong with water parameters, so please help!
According to the quick read strips, nitrate=20ppm (I did a 20-25% water change as normal this weekend.) Nitrite=0ppm, Hardness=75ppm, chlorine=0ppm, alkalinity about 40ppm, and here's the real problem- ph=6.2 (or lower, because the test won't go any lower than that.) Ammonia is at 0ppm. Tank temp at about 70*F, 20 gallon that now has 11 guppy fry (in a breeder net), 3 female adult guppies, 8 mini cory catfish, 4 nickel to quarter size mystery snails, and a handful of live and plastic plants. Filter includes a sponge filter and a biological filter. Light is from a simple floor lamp that I have directed at the tank and doesn't appear to affect temp. It IS in front of a window that gets indirect sunlight, but I am very limited in that location because I have a studio apartment and there's not much space to move things around.
I have done everything I can think of to raise the pH, and I am afraid that messing with it will simply add stress. Previously, when everybody was ok, I saw the pH problem and tried to adjust with chemicals, but the change was only temporary (and hard to predict!) so I gave up. I added empty shells from some dead mystery snails, then some cuttlebone- no change. Tried almond leaves, no change. Seems like nothing I do helps. After testing the pH of my tap water (after a 24hr period of sitting out,) it's 7.6 (or higher, test won't go any higher!) That really confused me- I'm adding water that's slightly basic, but ending up with a tank that's slightly acidic??
My main questions are: Should I get a heater to increase the temp? (Temp may fluctuate over night, from 69.8*F-73*F during the day. I worry about this too, but this is also not new.) Is there any OTHER trick to raise pH? Is there anything I can do for the specific fish having trouble right now, and how can I prevent this from happening to the others? Does this sound like anything anyone else has seen before?
Thank you for any info. This is my third try with red albino guppies (I just think they are so beautiful) and I would hate to fail again. :/ Well, aside from that, I really hate to see them suffer. Can't think of anything new that I did to cause this! Help is appreciated, if you need more info just ask. (Also, are the albinos more sensitive than non-albinos? I seem to get that sense.)