Two Questions

[CatoeSc]

1. Can you define brackish water? Is this simply fresh water with any amount of salt, or is it fresh with a certain amount of salt per gallon?

2. I am using reverse osmosis water from my LFS for my tank. It's just easier and safer IMO to use the same water every time minimizing the differences in the water. Since setting up my son's new tank, the pH has risen from 7.6 to 8.2. What would cause this to happen? I'm not extremely concerned about this as this is in range for nearly all his fish, but I don't want it to keep rising. Obviously, changing the water helps, but any ideas of what's going on? FYI, I've slowly added aquarium salt. Not a whole lot, there's about 0.8 tspn per gallon, which feeds back to the original question.

 

[fort384]

As you add salt, the pH is going to increase.

Brackish water is generally regarded to have a specific gravity of 1.005 to 1.010.

 

[CatoeSc]

Okay. Is 8.2 okay, or should I try to do something decrease it? Also, how do I measure the water weight?

 

[fort384]

8.2 is probably fine. What fish are you planning to keep?

To measure specific gravity or salinity, the best tool in my opinion that balances cost and quality of measurement is a decent refractometer. Hydrometers are only a little cheaper, and are not as reliable. The electronic meters are great, but are too much money when a refractometer does just fine, imo.

Here is a good one:
Refractometer for reading salinity w/ Free Calibration fluid - Bulk Reef Supply

looks like it is out of stock, but I am sure they will have more soon. They sold a bunch over the last few weeks as they were on super-sale for Christmas.

 

[phin]

1. Can you define brackish water? Is this simply fresh water with any amount of salt, or is it fresh with a certain amount of salt per gallon?

2. I am using reverse osmosis water from my LFS for my tank. It's just easier and safer IMO to use the same water every time minimizing the differences in the water. Since setting up my son's new tank, the pH has risen from 7.6 to 8.2. What would cause this to happen? I'm not extremely concerned about this as this is in range for nearly all his fish, but I don't want it to keep rising. Obviously, changing the water helps, but any ideas of what's going on? FYI, I've slowly added aquarium salt. Not a whole lot, there's about 0.8 tspn per gallon, which feeds back to the original question.

brackish water is water with .5 - 28 ppt salt or .5 - 30 grams/liter of salts, or a specific gravity of 1.005 up to 1.028.

The salt you are adding is not having an effect on pH. Salt on its own has no Ph level but when put in water, the solution contains free ions of Na+ and Cl-. Both ions do not react with water as their alkaline and acid properties cancel out. As a result, the solution is neutral.

The amount of salt you are putting in, 0.8 teaspoons per gallon is roughly equivalent to 4.5 grams of salt per gallon, or 1.18 grams/liter, resulting in an estimated specific gravity of 1.0018, not enough salt to become even a mild brackish solution.

If you are putting pure RO water into the tank and not buffering your water, some of the decorations, gravel, or other items might be responsible for increasing the pH of your water.

What is your Kh? What is the Gh?

In my opinion, if using pure RO water, your best solution would be to use Seachem's Neutral Regulator to condition your water. It will do everything prime or amquel does, but will also buffer your water to maintain a pH of 7.0. From there you can add whatever you desire to achieve your optimum pH, if it isn't 7.0.

I wouldn't be concerned with the pH of 8.2 as much as I would be concerned with what is causing the pH to change and if the water is properly buffered to prevent pH swings.

 

[CatoeSc]

Your helpful, but over my head. . What are Kh and Rh?

 

[CatoeSc]

Your helpful, but over my head. . What are Kh and Rh?

I mean Gh

 

[CatoeSc]

I mean Gh

 

[frank98284]

i believe he is talking about water hardness a water hardness of 6 i would believe provide a buffer to help keep your ph stable

 

[phin]

Basically, The salt is you are adding is not doing harm and is not making your tank brackish.

If you are using RO water you need to buffer the water to guard against pH swings. One measure of buffering ability is Kh, or Carbonate Hardness, which is the measure of the alkalinity of your water caused by the presence of carbonate and bicarbonate anions (it is not a measure of total alkalinity). In my opinion, the easiest way to buffer RO water is to use Neutral Regulator. It is made by seachem and is one of the products you can usually find in just about every petco, petsmart, pet supermarket or LFS.

 

[Wyomingite]

1.028 is significantly higher than the average specific gravity of most of the marine waters in the world. The Indo-Pacific ranges from 1.022 to 1.025 and the Carribean from 1.023 to 1.026. Generally speaking, 1.025 is considered average marine specific gravity. IIRC the Red Sea is the only living body of sea water from which aquarium species are regularly seen in the trade that regularly has specific gravities reading at 1.028 or over.

CatoeSc, fresh water has a specific gravity of 1.00. For the aquarist's purpose a specific gravity up to 1.005 is low salinity brackish, from 1.006 to 1.015 is moderately brackish and from 1.016 to 1.022 is highly brackish. A specific gravity above that is marine. Specific gravity is measured using a refractometer or a hydrometer, as stated, and is a must if ya intend to maintain brackish species. GH is general hardness and KH is carbonate hardness. The hardness is what buffers the pH and keeps it stable. For now I'll ignore the chemistry how this works and focus on yer problem/question.

From your post, I get the impression you have no intention of a maintaining a brackish tank, but rather are concerned about the salt ya have already added and the rising pH. The salt ya have added is negligible and not nearly enough to create a brackish environment. It also does not have the right components to increase the pH of your water. Unless you are attempting to breed sensitive species that require soft water to breed, or unless you are planning a marine reef tank and are looking to control nutrients by using RO water and a salt mix to control water chemistry, I would discourage using RO water. It is not necessary for a plain FW tank. Tap water in most places has the minerals in it to buffer the water properly and to prevent rapid swings in pH, as long as regular water changes are performed.

Due to the metabolism of organisms in the aquarium, from the beneficial bacteria to the fish, water in an aquarium typically acidifies and the pH drops over time (this is where the buffering capacity of the water comes into play). If your pH is rising, there is definitely something going on. Several things come to mind.

First, did ya cycle the tank? What is the ammonia reading in your tank? An increase in ammonia will elevate pH somewhat.

Second, what kind of substrate/gravel/sand are ya using? What other decorations in the tank? The rise in pH may be due to something leaching into the water.

Third, what method are ya using to test pH? Have ya verified the pH with another kit? We need to ensure that the readings are accurate. The problem could be something as simple as an outdated test kit providing an inaccurate reading.

The pH may not be a concern now, but any unexplained change in water chemistry should be investigated and corrected.

WYite

 

[CatoeSc]

Wyomingite, thanks for the info. Being relatively new to the hobby, I've just bought RO water from the LFS where I've been buying fish. It made sense to me that there would be a bit less risk since I don't know how to prep tap water for the tank plus it's the same water he is using in his tanks. I realize that each tank is going to change somewhat overtime, but my hope was that at least the water would be as consistent a possible. I did cycle the tank. As of 2 days ago, my ammonia and nitrites were back to zero, but of course the nitrates are still a bit elevated as expected.

I'm only adding a bit of salt b/c I was told it is good to have for most tropical fish in helping their slime coat and coloring.

I only have common decoration from the pet store that I cleaned with tap water before putting in. Most have been there all along with the exception of 2 plastic plants I added a few weeks ago.

I us an API kit and all the expiration dates are years out. What do you use to test hardness?

 

[CatoeSc]

Wyomingite, thanks for the info. Being relatively new to the hobby, I've just bought RO water from the LFS where I've been buying fish. It made sense to me that there would be a bit less risk since I don't know how to prep tap water for the tank plus it's the same water he is using in his tanks. I realize that each tank is going to change somewhat overtime, but my hope was that at least the water would be as consistent a possible.

I did cycle the tank. As of 2 days ago, my ammonia and nitrites were back to zero, but of course the nitrates are still a bit elevated as expected. I'm only adding a bit of salt b/c I was told it is good to have for most tropical fish in helping their slime coat and coloring.

 

[phin]

Wyomingite, thanks for the info. Being relatively new to the hobby, I've just bought RO water from the LFS where I've been buying fish. It made sense to me that there would be a bit less risk since I don't know how to prep tap water for the tank plus it's the same water he is using in his tanks. I realize that each tank is going to change somewhat overtime, but my hope was that at least the water would be as consistent a possible.

I did cycle the tank. As of 2 days ago, my ammonia and nitrites were back to zero, but of course the nitrates are still a bit elevated as expected. I'm only adding a bit of salt b/c I was told it is good to have for most tropical fish in helping their slime coat and coloring.

Do you know what your tap water readings are? I believe DFW water comes from reserviors and is surface/rain water. I know the tap water in Plano tastes like algae. I'm guessing your tap water is pretty soft with a neutral or slightly acidic pH (but thats just a guess).

Depending on how inconvenient constantly doing RO water changes are you might want to consider using your tap water, conditioned with prime, for your water changes. That should add any buffering capacity you need in order to keep a stable pH. I would continue to add salt at the same amounts you presently measure.

If you want to keep using RO water (there's nothing wrong with that) then add neutral regulator (by seachem) to achieve proper buffering capacity and a stable pH of 7.0. If you use neutral regulator you don't need to condition with prime, as neutral regulator will condition your water too. I would still add salt.

 

[CatoeSc]

Phin, I really don't know much about Ft Worth water, but I may be about to learn. Just bought a 40B from Petsmart, and don't want to take 4 trips to the LFS to get water.

How do I prep my tap water for the aquarium? I assume I need to prep it before it goes in the tank?