Ph from tap reads 7.5 but in tank reads 8.2

[maritzsa]

Just like the title says; my ph with the API master kit gives me a 7.5 ph reading (using the high range ph) and when I measure my tank I get 8.2. The tank is 5 gallons, has a sponge filter, houses one batta and has fluval stratum capped with sand. I read that aeration causes ph readings to go high. Is that possible? Or can NilocG Thrive raise my ph?
There are no rocks in the aquarium only a piexe of drift wood with java moss, fern, and an amazon sword.

 

[Byron]

There are two likely reasons. First, could be the fluval stratum. The second is the tap water test may be inaccurate, if you did not out-gas the CO2. Lety a glass of tap water sit 24 hours, then test pH. This will be more accurate. When this is known, or if you already did the out-gas of the tap water, the fluval stratum seems likely.

Thrive I assume is the liqud plant fertilizer; nothing I could se ontheir website mentions pH changes, and this is less likely to occur with these products. Aeration is not going to be the issue either. This might show up in the aquarium water due to the diurnal pH fluctuation, but not as you describe here.

 

[maritzsa]

There are two likely reasons. First, could be the fluval stratum. The second is the tap water test may be inaccurate, if you did not out-gas the CO2. Lety a glass of tap water sit 24 hours, then test pH. This will be more accurate. When this is known, or if you already did the out-gas of the tap water, the fluval stratum seems likely.

Thrive I assume is the liqud plant fertilizer; nothing I could se ontheir website mentions pH changes, and this is less likely to occur with these products. Aeration is not going to be the issue either. This might show up in the aquarium water due to the diurnal pH fluctuation, but not as you describe here.

I didn’t think stratum would do anything because it is supposed to lower ph rather than raise. I am gonna do the 24 hour water test tomorrow and if i still get low on tap high in tank ig i might remove stratum

 

[Byron]

I didn’t think stratum would do anything because it is supposed to lower ph rather than raise. I am gonna do the 24 hour water test tomorrow and if i still get low on tap high in tank ig i might remove stratum

Sounds good plan. I didn't mention it previously, as it was not the direct issue, but these plant substrates do have some problems for fish and/or water chemistry. Bacterial issues, causing ammonia, causing nitrates, etc. Substrate fish can also be affected by some of them. Worth realizing.

 

[Myraan]

Is it coral sand?

 

[maritzsa]

Sounds good plan. I didn't mention it previously, as it was not the direct issue, but these plant substrates do have some problems for fish and/or water chemistry. Bacterial issues, causing ammonia, causing nitrates, etc. Substrate fish can also be affected by some of them. Worth realizing.

I actually did a quick test where i put an airstone in a small cup of tap water and the ph did go upto where it is in the tanks. Also I did some KH and GH readings which came up to be , 170ppm KH and 55ppm GH and the ph is 8.2. Are these parameters okay? im worried my low GH means my fish aren’t getting the minerals they need like calcium, magnesium. The Thrive fertilizer has these minerals in it will that also benefit the fish

 

[Byron]

I actually did a quick test where i put an airstone in a small cup of tap water and the ph did go upto where it is in the tanks. Also I did some KH and GH readings which came up to be , 170ppm KH and 55ppm GH and the ph is 8.2. Are these parameters okay? im worried my low GH means my fish aren’t getting the minerals they need like calcium, magnesium. The Thrive fertilizer has these minerals in it will that also benefit the fish

That settles the pH issue. The actual pH of your tap water is 8.2 so you now know that.

The GH depends upon the fish species. Generally speaking, there are fish that must have moderately hard or harder water--livebearers, some rainbowfishes, rift lake cichlids to name a few--and these assimilate the calcium and magnesium from the water which continually enters the fish. Then there are the soft and very soft water species that do not need any minerals in the water, and will be better without. They have evolved with a physiology to function best with mineral-poor water. In the middle are a number of fish species that may occur in soft water but can manage with a moderate GH.

The GH is the most important parameter (aside from temperature) and 55 ppm [= 3 dH] is very soft water. Forget any of the hard water fish mentioned abo0ve, they will not survive. But most all of the soft water species (tetras, rasboras, danios, barbs, catfish, loaches, gourami, dwarf cichlids) will be fine.

The KH at 170 ppm [= 9 dKH] is a bit high so the pH will not likely lower much, but once the aquarium is established this will work out. It is best to leave the pH alone, a fluctuating pH is more of a problem for fish that a stable one. The only way to lower the pH is to reduce the KH, and this means diluting the tap water with "pure" water, but I would not start down that road yet. If you can use your source water as it is, it will make life much easier when it comes to water changes.

 

[maritzsa]

That settles the pH issue. The actual pH of your tap water is 8.2 so you now know that.

The GH depends upon the fish species. Generally speaking, there are fish that must have moderately hard or harder water--livebearers, some rainbowfishes, rift lake cichlids to name a few--and these assimilate the calcium and magnesium from the water which continually enters the fish. Then there are the soft and very soft water species that do not need any minerals in the water, and will be better without. They have evolved with a physiology to function best with mineral-poor water. In the middle are a number of fish species that may occur in soft water but can manage with a moderate GH.

The GH is the most important parameter (aside from temperature) and 55 ppm [= 3 dH] is very soft water. Forget any of the hard water fish mentioned abo0ve, they will not survive. But most all of the soft water species (tetras, rasboras, danios, barbs, catfish, loaches, gourami, dwarf cichlids) will be fine.

The KH at 170 ppm [= 9 dKH] is a bit high so the pH will not likely lower much, but once the aquarium is established this will work out. It is best to leave the pH alone, a fluctuating pH is more of a problem for fish that a stable one. The only way to lower the pH is to reduce the KH, and this means diluting the tap water with "pure" water, but I would not start down that road yet. If you can use your source water as it is, it will make life much easier when it comes to water changes.

Thank you, the aquarium has been running for a month and I got 2 others that have been running for 4 months. I recently moved houses ( I also had 8ph tap water) and when I got to new house and tested tap and I got 7.5, I was ecstatic, because now I could keep stuff like tetras (I haven't bought any yet). However the comparison with in-tank vs tap confused me and now thanks to you I have learned its 'cause the dissolved co2 makes the reading lower. I keep 1 betta in 5 gallon, 1 female in 3gal temporarily because the 10 gallon she was in, my male and female mated and I am raising fry very succesfully for 4 weeks now. All of my fish and the fry seem to be doing well in this high ph water, and I also did a test with Thrive fertilizer and it does increase GH in tank. I got 25-27 fry since the start and haven't lost any, they all have their fins right now so I assume the GH boost from fertilizers helped them grow their bones etc well. Something I do wanna know lastly which I can't find much about, what indication would I see from bettas that the ph is bothering them. So in case something pops up I will know its the ph

 

[Byron]

If the pH remains steady once the tank's biological system is well established, it should not cause issues. I have so little experience with pH problems since I have always had very acidic water and have fish suited to that.