PH advice

[Elephant nose 4]

Hi ive been noticing lately my Ph in my elephant noses tank has gone from 6.6 to 6.4 , today I checked again and it was 6.2 now I have crushed coral but hesitant if I'm doing the right thing adding it to my filter? Or do I leave the pH alone?
Any help would be great

 

[TwoTankAmin]

pH level is basically a function of KH.

pH​

pH refers to water being either an acid, base, or neither (neutral). A pH of 7 is said to be neutral, a pH below 7 is ``acidic'' and a pH above 7 is ``basic'' or ``alkaline''. Like the Richter scale used to measure earthquakes, the pH scale is logarithmic. A pH of 5.5 is 10 times more acidic than water at a pH of 6.5.

Buffering Capacity (KH, Alkalinity)​

Buffering capacity refers to water's ability to keep the pH stable as acids or bases are added. pH and buffering capacity are intertwined with one another; although one might think that adding equal volumes of an acid and neutral water would result in a pH halfway in between, this rarely happens in practice. If the water has sufficient buffering capacity, the buffering capacity can absorb and neutralize the added acid without significantly changing the pH. Conceptually, a buffer acts somewhat like a large sponge. As more acid is added, the ``sponge'' absorbs the acid without changing the pH much. The ``sponge's'' capacity is limited however; once the buffering capacity is used up, the pH changes more rapidly as acids are added.

Buffering has both positive and negative consequences. On the plus side, the nitrogen cycle produces nitric acid (nitrate). Without buffering, your tank's pH would drop over time (a bad thing). With sufficient buffering, the pH stays stable (a good thing). On the negative side, hard tap water often almost always has a large buffering capacity. If the pH of the water is too high for your fish, the buffering capacity makes it difficult to lower the pH to a more appropriate value. Naive attempts to change the pH of water usually fail because buffering effects are ignored.

In freshwater aquariums, most of water's buffering capacity is due to carbonates and bicarbonates. Thus, the terms ``carbonate hardness'' (KH), ``alkalinity'' and ``buffering capacity'' are used interchangeably. Although technically not the same things, they are equivalent in practice in the context of fishkeeping. Note: the term ``alkalinity'' should not be confused with the term ``alkaline''. Alkalinity refers to buffering, while alkaline refers to a solution that is a base (i.e., pH > 7).

from https://fins.actwin.com/aquariafaq.html

Do you have a KH test kit?

Depending on the amount, crushed coral can raise both KH and GH. It is basically calcium carbonate. The calcium contributes to GH (hardness) and the carbonate to KH.

And, no you do not want the pH to keep dropping. It is getting close to the bottom of the range for this fish (pH 6.0-7.5 according to https://www.seriouslyfish.com/species/gnathonemus-petersii/).

Finally, can you please answer as many of the following as you can:
Your Tap water pH and KH
Your tank water KH
Tank size
Water change amount and frequency

 

[Colin_T]

Make sure you do big regular water changes and gravel clean the substrate each time you do a water change.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Add some more crushed coral, limestone or shells to the tank/ filter to stop the pH dropping. Add a bit and monitor the pH over 2 weeks. If it continues to drop, add a bit more. When the pH stabilises, stop adding the coral.

 

[Elephant nose 4]

Hi, went to use my kh/gh test and it's out of date so I'm waiting on a new one, pH from tap is 6.8 -7.0 , I do 50% pwc and always go over the top of the sand, pwc I've upped to 2x weekly hoping this helps, I have 200grams of crushed coral but wasn't sure where to start.
Thank you

 

[Colin_T]

I have 200grams of crushed coral but wasn't sure where to start.

Start with that and add another 200g in a couple of weeks if it keeps dropping.

GH and KH does not normally change much throughout the year. You can also find these on your water company's website or by telephoning them. If you want to be 100% certain about the GH and KH, take a sample of tap water to the local pet shop a couple of times a year and have them test it for you. It's cheaper than buying the kits and having them go off because they aren't used.

If you need to keep the test kits for a long time, try to keep them in a cool dark spot. I kept my test kits in an icecream bucket with a lid on, and had that on the bottom shelf of my fridge. Just make sure children and animals can't get to the kits because most of the reagents are poisonous.

 

[Elephant nose 4]

Start with that and add another 200g in a couple of weeks if it keeps dropping.

GH and KH does not normally change much throughout the year. You can also find these on your water company's website or by telephoning them. If you want to be 100% certain about the GH and KH, take a sample of tap water to the local pet shop a couple of times a year and have them test it for you. It's cheaper than buying the kits and having them go off because they aren't used.

If you need to keep the test kits for a long time, try to keep them in a cool dark spot. I kept my test kits in an icecream bucket with a lid on, and had that on the bottom shelf of my fridge. Just make sure children and animals can't get to the kits because most of the reagents are poisonous.

Thank you very much for the help

 

[Byron]

When I decided to buffer one of my tanks, a 5-foot 115g, I used about 2 or 3 tablespoons of dolomite in a nylon bag in the canister filter, and it kept the pH in the mid 6 range for years. The tap water pH at that time was 5 or lower, and GH/KH zero. I did not measure the GH or KH in the tank back then, but the pH did remain around 6.4 to 6.5 for several years. And I did water changes every week of roughly half the tank with no other additives aside from the dolomite in the filter.

 

[Elephant nose 4]

When I get my ph up to where I need I take it I leave the crushed coral in?

 

[TwoTankAmin]

The crushed coral works by dissolving in the water because of the acid [H. The more acid, the faster it will dissolve. So over time one must replenish it. What you are looking to do is to discover the amount of coral you need to have in the filter to keep things fairly stable. Once you can determine that, all you need to do is top up the coral when it has lost about 1/2 of its volume or if you notice the pH is dropping.

 

[StevenF]

When I get my ph up to where I need I take it I leave the crushed coral in?

Once the PH exceeds 7 the coral will stop dissolving and the PH should stabilize. my tank will also go acidic. I put a deocorative sea shell in the water. now the PH say very close to 7 all the time. I have to replace the sea shell about once a year
once a year.

 

[Elephant nose 4]

Thank you all for the information it's really helpful.