Rebooting my 29g Tank

[endoubleu]

Hello,
Tank: 29g
Lighting: 1x T8 5500k
Filter: AquaClear 70 with bio and sponge only, recently added carbon
Substrate: 2.5" layer of flourite and playsand

I was on a budget when I started this tank, both money and time-wise. I became busy soon after setting it up and didn't have time to take proper care of it.

Right now, all of my plants are pretty much dead. I've removed it and cleaned out the filter. The fishes are doing well. My dilemma is here:
My pH is sitting at 6.0. If it's lower, then the indicator isn't able to show it. Even after cleaning and changing the sponge in my filter, and weekly 30% water changes, the pH goes back to 6.0 after 24 hours. This has been the same for a month now. my kH is sitting at ~2 degrees (0-50ppm).

I think that I need to raise my kH about 2 degrees and my pH to at least a 6.5.

1. What are some safe methods to do so without stressing out the fish?
Also I'd like to start planting again and I can afford a Co2 regulator system.
2. Should I start planting while treating the water?
3. Would planting help the kH and pH levels?
4. When should I start adding the Co2? A few months after planting in low light? When I switch to T5HO lighting? Co2 drops pH levels so I would have to get the kH up to prevent pH swings. How would I go about this?

Thanks.

 

[Iodizedfate]

Have you tested your ammonia, nitrite and nitrate levels?

It sounds like you might have "old tank syndrome" which if that's the case you want to be careful with your water changes.

What happens is the ammo, trite and trate build up and cause the pH to crash. This puts the tank in a weird limbo thing where the ammo and trite aren't as toxic as normal and the fish build a tolerance.

Best thing to do is to perform gradual water changes, changing a little bit every day (15% - 20%) until you get the ammonia and nitrite down below .25

You want to avoid sudden changes to the tank because if you bring your pH up too quickly it will toxify the ammonia again and that would put the fish into shock and kill them.

You could try moving the fish to another tank but you have to make sure you use a slow acclimation method.

Here is a link that goes into detail about old tank syndrome.

Old Tank Syndrome

As for plants my guess is that they would help.

 

[Bottomfeeder88]

A few holes in the premise, but a very interesting article nonetheless. I'm relatively new to fish keeping and have never heard of old tank syndrome,yet i have seen it in other tanks often. good read.

 

[endoubleu]

I should've mentioned that before. My ammonia, nitrite, and nitrate levels are all near 0. I haven't had a spike since it finished cycling. I've had 2 sponge and a bio in my filter. Recently I added carbon to see if something in the water is causing the pH to change.

[Edit]: My water did evaporate and I've refilled it as the article says, but then my water should have better hardness. I'll start with daily 10-15% and see if the pH changes slowly. If the pH stabilizes, I'll add plants and the T5HO. I'll start Co2 after a couple of months if everything is still OK. Is this a good plan?
Also, my tap water has a kH of 4 and pH of 7 even after 24 hours.

 

[Iodizedfate]

That's what I wood do with. I would be vary wary of any large changes to the tank but go with tiny water changes daily and see if that helps.

Have you had any progress with the tank?