Ph affecting swordtail?

[Soilwork]

Hello.

My swordtail has been acting very strange for the past week or so. She is constantly extending all her fins as she swims and has become skittish. She darts and jumps whenever I go near the tank and I noticed her anal fin was a little frayed. This is unusual and all my other fish are acting normal although I have noticed the same fin fraying on a couple of my cardinals.

I have been injecting co2 for the past few weeks and wonder if this is the issue. My Kh is rather low. I know the test kits are poor but my water quality report confirms this also. I had a 1.5ish bubble rate and my drop checker was green, not lime but just green. I check my ph with a liquid test and every time I have done this in the past 3 years it has given me the same blue colour. The high range always gives me the lowest figure so I concluded my tank water ph was and has always been 7.5, my water report would confirm this also. When I checked my ph a couple of days ago it had turned a strange yellow colour. The yellow on the API card suggests a ph of 6.0 but I think it may have been lower. I have a ph meter on order now for a slightly better degree of accuracy when determining ph. I have turned the bubble rate down now and added crushed coral to the canister filter. I checked ph again today at the height of the co2 period and my ph is back to the blue 7.5. The drop checker is bluey-green. The problem is it's been a day or so since I made these changes and my sword is still acting strange. I was sure the ph was the problem but now I am not so sure. I haven't introduced anything new to this tank for a long time so I don't believe it's parasites or anything. Only things I have done is removed lots of plant mass that could have resulted in less co2 being used which would mean a faster and further ph drop. After a 50% water change the other day she was fine but changed again as soon as the co2 had come on. Maybe the misting bothers her?

I researched acidosis and the symptoms do seem consistent. Darting, jumping and irritated skin. Perhaps that is why her fins are stuck out so she is not irritating her scales? I also redirected my flow but I don't think this could be the problem. Does acidosis seem viable and would the fish recover from this?

Thanks

 

[alto]

Fin fraying - especially on multiple fish - makes me suspect water quality (or fish aggression but this is usually apparent, even if you don't see the actual fin nipping, the behaviour of the harassed fish alters)

Swords like most live bearers do better in harder water (many shops also add salt).

I haven't introduced anything new to this tank for a long time so I don't believe it's parasites or anything.

this is a common misconception - fish have a "normal flora" of varied microorganisms, many of which can increase to disease states when fish become stressed (water quality, aggression, environmental factors including too cold, too hot, too bright, shadows/vibrations bagging, shipping etc); rapid increase in external parasites (skin & gills) is very common in stressed fish.
(external fungal & bacterial infections, internal bacterial infections, generally occur slower & tend to reflect longer term stressors; the former usually respond well to improved water quality, the latter are often fatal)

At present I'd just focus on water quality, try daily 25 - 35% water changes, decrease CO2 levels for a week or so, increase aeration during non-CO2 times ... it sounds as if you noted & corrected a pH effect.
I doubt the "misting" bothers her, but the increased C02 & pH changes may be more distressing than usual when she's already in some physical stress, eg, if she's suffered any gill tissue damage (whether parasite or water quality dependent), she will be much less able to extract sufficient oxygen from water - if possible, you might move her to a hospital tank where you can maintain stable water conditions for at least a couple weeks.

 

[Soilwork]

Alto, thank you for the thoughtful response. I would be more inclined to agree at this point that it is a water chemistry issue. When I did a 50% water change as part of my EI routine her behaviour completely changed. She went back to doing what swordtails do, gliding round, picking at plants and hardscape. I've had her for 3 and a half years and she has always been one of my favourite fish. I agree swords prefer harder water and thinking about it now could be the reason others I had kept with her had not fared so well in the same time frame. They never spawned either. Having said that she has been fine all this time. Then I always did run coral in the filter but I had removed the coral prior to co2 injection (i can't think why now) so maybe that has had an effect. The only other changes have been the addition of EI macro's and co2 injection. She doesn't seem to be gasping or struggling for oxygen and would sometimes rest near the bottom. I'm religiously doing 50% water changes now and cleaning the filters regularly in an attempt to keep algae at bay. For this reason I don't think it's a poor water quality issue as in the dirty sense. I watch a lot when I come home from work, even more so now this problem has arose and I have never witnessed any nipping but could be possible. The harlequins have become much more territorial now the extra vegetation has gone in.

As for parasites, I'm just not sure. I run a UV filter and change lots of water and gravel vac where I can. I have never seen parasites in this tank. Could perhaps be a bacterial issue but again her symptoms relinquish after lots of water is changed.

Carbon injection is down now and I have removed my reflectors to compensate for the lower carbon availability. I'll just have to keep my eye on her. All my other fish are naturally from soft waters and don't seem to show any of the same symptoms. My shrimp do seem to prefer the lower co2 or higher ph as well as I see them come out a lot more from under the bogwood.

 

[Soilwork]

Update: came home yesterday to sword still acting strange. Always perks up after co2 injection has gone off so I turned it off completely for today. Bps was down at about 1 bubble every 2 seconds. Ph pen is is due today but I suspect it was 7.5. My cardinals fins are getting worse. Eroding now quite badly. Have to open myself up to a possible bacterial infection unless their is nipping after lights out. All 6 cherry barbs and all 6 harlequins are unaffected at present. All my 5 shrimp are out now where as before they would hide under my wood.

Still ongoing will check with my other half how the sword is has been whilst I'm a work. She has witnessed the jumping and skittish behaviour herself so she knows what to look for.

Water change tonight also as I didn't get home till late last night.