Help With Persistent Low Ph

HI everyone, thanks in advance for any advice.

Ive been struggling for about a year, ever since I set this tank up, with very low PH. I have never had this problem before with other tanks. There is obviously something in my set up that I'm missing that's causing the problem and I'm looking for any help diagnosing it.

I have a 240l aquarium, that houses 2 medium fancy goldfish and 2 small fancy goldfish.

It has a 306 Fluval external filter.
For decor it has sand as the base, is very heavily planted and a few stones and an aquarium safe, fake branch
I did have some driftwood in the tank though I took that out a few months ago as I thought it might be the culprit, but no difference.
2 large bubblers.

The water quality just tested as aminia 0.2, nitrite 0, nitrate 0, PH 6.8
The temp is a bit high as its very hot here 28'C. I have added in a couple of bottles of freezer cooled water to cool it down.

At the moment I'm having to put PH up in every few days to keep it up.

The only differences in this tank set up that ones I've had before is I've used aquarium sand for the first time, an it's much more heavily planted. But as far as I understand they shouldn't' lower PH?

All ideas welcome. Or let me know if you need any more info.

Blink

 

I am having th same problem with my Georgia water .. people have told me crushed corals and real seashells help it naturally . I’m using a buffer from seachems products to try to increase mine. My low ph has been affecting my tank from cycling I think. It’s been going for a month...-yikes -

 

6.8 pH isn't bad at all. Close to neutral. Is there a reason why you want to increase pH?

Crush coral is the easiest and safest way to increase pH. A cup for every 40 gallons will bring it up about 1 point, so you be looking at 7.8.

But if your fish is doing well, I wouldn't change it.

 

It's at 6.8 as I've been medicating with PH Up most days. without his is quickly slips down to 6.0 (that's as low as my test shows)
I can tell when it drops as the oldest goldfish starts gasping at the surface. They seem most happy when its over 7.4.

I've ordered some crushed coral, hopefully here by wed, so I'll give that a go to see if I can stabilise it.
Would you just put the coral into the tank? or does it need to be in the filter (If in the filter, which medium would you remove to make space, as a cup and a half is quite a big space?)

Thanks for your advice

 

Are you using chemicals to raise your pH? Not a good idea. That can just make the solution worse. Have you tried almond leaves?

 

The product I've been using is PH up by API


Ive ordered some coral. Would you recommend using almond leaves with the coral?

Also out of interest why would using chemicals make the problem worse? ( I believe you, I'd like to understand more). I can tell it doesn't solve the problem as its never gone away for me.

Thanks

 

Never tried coral with almond leaves, but I have cuttle bone with almond leaves. steady at 7.6 pH, as of the chemical question, chemicals usually just either kill your fish, cycle or do both.

 

My cycle is definitely off. My levels never get much higher than they are now. The fish seem ok, but I obviously need to resolve it.

I'm guessing that when I add coral/cuttlefish/almond leaves I should look out for a spike in ammonia?
Also new materials gradually?

Again would you add the leaves to the filter or is it ok/better to put them direct in the tank?