[ThatFunkyFish]

I have a 29 gallon tank which as of several months ago, housed a big fat Oscar. Oscar (that was his name too) eventually got sick and died. He had some nasty hole in the head and there wasn't much I could do.
After he died, I cleaned the tank as best I could and let it just sit filtering for about a month. I then put in some plants and let them adjust. Most of them didn't fare too well. I picked out whatever plants turned dark green, brown and mushy. Things started to balance out it seemed so I went and got some small fish. Just tetras. Most of them didn't fare too well either.
Cutting to the chase...
I now have 2 (gold pristella) tetras and they hearty and happy. The plants that are there are of three varieties of which I don't know the name of, and seem to be staying crisp and green.
Unfortunately, it wasn't until just recently that I decided to actually test my water. I know the nitrates were deathly high, which I've treated with a series of bi-daily water changes (which has lowered the nitrate levels dramatically, though they're still present).
My tank also suffers from extreme water hardness (gH) and yet zero alkalinity (kH). Needless to say, my pH is very low.
I'm glad that my two little Tetra troopers are keeping up the morale, yet I want my tank to get better! Someone please help!

 

[ladyonyx]

Well the only sure-fire way to get softer water is to get a RO unit. This will give you soft water, which is a good start. Your water definitey needs more buffering capacity (alkalinity) and the pH needs to be higher. Please give your water quality parameters in your next post. Depending on how much your pH needs to increase, you might just be able to add some crushed coral to your filter media or directly to the tank. There are many additives that can be used to buffer your water as well that work great in conjunction with crushed coral. Coral usually increases hardness though, so unless you start using RO water, your hardness would be through the roof.

 

[ThatFunkyFish]

a little more specifics about my water:
When I first tested the water my general hardness was around 300 ppm, nitrates at around 200 mg/L, an alkalinity of 0 and a pH of 6 or lower.
For the past 2 weeks or so I've been doing a water change of about 20% - 30% every 2 - 4 days.
Last I checked my nitrates were down to about 50 mg/L, hardness down to 200 ppm, still no alkalinity and a pH of 6.
I'm using a filter with carbon, certainly not over feeding, plenty of air being pumped in...perhaps this will help with someone helping me...

 

[WhiteGloveAquatics]

Why is your Ph that low? where do you live? what water source are you using?


Carbon is only good for a maximum of 7 days once exposed to moisture. if its older then that its chemically not doing a thing but taking up space.

You need to raise your Ph either with removing or adding something to the tank.

Fish can live in Ph as low as 3.8 with success and as high as 9.0. Ph isnt a problem most of the time.

I think you got some decor in the tank causing this problem.

 

[ladyonyx]

Until your alkalinity gets higher, you won't be able to keep your pH at a stable reasonable level. For starters, try testing the water you're using before you put it in the tank just to see how much of this problem is coming from the water alone and not from your tank. Maybe you need more aeration in your tank; that will raise the pH. Do you have a bubbler or an air stone? Try that and see if it helps

 

[beaslbob]

FWIW

Low pH , Low KH, and nitrAtes can all be corrected by thriving plants. I would add more with emphasis on fast growers like anacharis or vals.


my .02

 

[ThatFunkyFish]

I've thought about the decor being a problem. As for my water source, I've tested it using the same test strips I use for my tank, and everything is spot on. pH of 7, zero nitrates, nitrites, chlorine or ammonia, a general hardness that is neither too soft nor too hard and a relatively low, yet apparent alkalinity.
Although it's a 30 gallon tank, I have a pump designed for a tank twice the size, with a couple of tubes going into a couple of air stones. i don't think aeration is the problem.
I'd like to put more plants in, but I'm afraid they will die. perhaps I will go and make sure to get the same plants that are currently doing well in my tank.
as for the decor, i have one piece of driftwood that has been in the tank for some time now as well as a piece of faux drift wood. there are also some larger stones aside from my course substrate. The current decor that has me a little worried are a couple of pieces of larger white/transparent stones. I don't think they are halite or anything else that would be dissolving into the water (which may account for a high hardness but not for zero buffering ability.)
i don't want to add chemicals. i know that a stable alkalinity will help with the pH. what can i add to bring up the alkalinity yet not add to the hardness.

 

[flyin-lowe]

API liquid test kits are the most accurate and are used by more people then others. Strips are often not accurate. What kind of lighting do you have. How many watts?? Even for low light plants you should have 1-1.5 watts per gallon min. Good lights will help with the plants, and the plants will help with the water parameters.

 

[WhiteGloveAquatics]

Try removing those stones. if it still happens then its not the stones but I stay clear of any light color or white stones/rocks/boulders.