PH level won't go up even after water change and losing fish!

[FISH_r_FRIENDS]

Hey fellow fish friends,

I recently put a post up with a problem with one of my guppies having a limp tail and swimming odd, kinda not using his tail, but then recently passed away I did my water checks, everything ok, ph was a bit low at 6.4 so I did a water change to increase the ph, tap water here's is usually 7.4 and I keep it at 7 in the tank, then the next few days passed and my gourami fish died? I checked the ph snd it won't go up even though I do a test of the water with the stress coat mix already in (usually one capos enough for my tank size)
And when I put it in- its stays the same ph level of 6.4?? I have separated the other guppie as it is showing the same symptoms as his friend had before he passed and don't want to lose another fish, I have a product from api called proper ph 7, that I have used a few times before and it worked a treat but when I add it now it doesn't have the desired effect, I also have a plant in there so I'm hesitant doing it too much as it says not to use with living plants- but once in a while I dnt think will have too much of an effect, no?

Tank 25 litres 61length x15deep x25high
Temp 28
Aqua 20 pump
One living plant on tree bark
6 neon tetra fish
2 mollies
One guppie

Gravel bed
Last water change this morning of 7 litres
Stress zyme added
Ph still 6.4
Sorry of the essay

Thanks so much

X

 

[cfosgate]

Sometimes in an eatablished tank you can have a low ph due to the organic waste that builds up from plant leaves that have died, fish waste etc... I would recommend a thorough cleaning of the substrate with your gravel vac. Also check the filter media and rinse it in recently changed tank water to clean waste from that. If you're still having an issue baking soda also works really well to bring your ph up. But do it slowly no more than .5 per day if possible. Best way to add baking soda is to dissolve a 1/4 teaspoon in a small cup containing tank water. Add this mixture to your tank slowly and just a little at a time, say 2 oz a day while monitoring your ph level.

 

[FISH_r_FRIENDS]

Great thanks I'll give it a try in the morning fingers and toes crossed