Best GH, KH and pH for a 5 Gallon Aquarium

[Rigatoni]

I set up a 5 gallon freshwater aquarium last week, and stocked it with 4 different types of fish (7 total).

At first the water quality seemed great: the water was clear, the ammonia registered basically naught, and everything else came up as safe when tested.

I noticed Alkalinity (KH) was high (over 300), and pH was about 7 or 8, and Hardiness (GH) was basically 0. I wasn't sure if any of this was anything to worry about as the test strip instructions didn't say, and I couldn't find any definite answers online.

This past weekend, I noticed the water was unusually cloudy, and a swarm of bubbles were forming around the water filter casing and edges of the aquarium interior. I think this was due to overfeeding as I was trying to find out exactly how much to feed them during the day; there was a lot of waste accumulating on the gravel and ammonia quickly rose to 1 mg/L (stress).

Sadly, I just lost two neon tetras, and am in the process of giving the aquarium a deep cleaning. I wonder if anyone know what the best Hardiness (GH), Alkalinity (KH) and pH would be for a 5 gallon freshwater aquarium? Or if anyone knows a good source to find out?

 

[Darkhorse]

I would suggest a call to a fish expert at a large pet store.

You've probably googled "aquarium chemistry" or "ideal aquarium chemistry parameters" already...

 

[Occams Barber]

I set up a 5 gallon freshwater aquarium last week, and stocked it with 4 different types of fish (7 total).
View attachment 302206

At first the water quality seemed great: the water was clear, the ammonia registered basically naught, and everything else came up as safe when tested.

I noticed Alkalinity (KH) was high (over 300), and pH was about 7 or 8, and Hardiness (GH) was basically 0. I wasn't sure if any of this was anything to worry about as the test strip instructions didn't say, and I couldn't find any definite answers online.

This past weekend, I noticed the water was unusually cloudy, and a swarm of bubbles were forming around the water filter casing and edges of the aquarium interior. I think this was due to overfeeding as I was trying to find out exactly how much to feed them during the day; there was a lot of waste accumulating on the gravel and ammonia quickly rose to 1 mg/L (stress).

Sadly, I just lost two neon tetras, and am in the process of giving the aquarium a deep cleaning. I wonder if anyone know what the best Hardiness (GH), Alkalinity (KH) and pH would be for a 5 gallon freshwater aquarium? Or if anyone knows a good source to find out?

This article covers all the standards you've mentioned along with the cloudiness problem. It also includes a table setting out optimum Ph etc for different types of fish.
Freshwater Aquarium Water Quality: The Nitrogen Cycle & Optimal Water Chemistry (aqueon.com)

OB

 

[topher694]

I set up a 5 gallon freshwater aquarium last week, and stocked it with 4 different types of fish (7 total).
View attachment 302206

At first the water quality seemed great: the water was clear, the ammonia registered basically naught, and everything else came up as safe when tested.

I noticed Alkalinity (KH) was high (over 300), and pH was about 7 or 8, and Hardiness (GH) was basically 0. I wasn't sure if any of this was anything to worry about as the test strip instructions didn't say, and I couldn't find any definite answers online.

This past weekend, I noticed the water was unusually cloudy, and a swarm of bubbles were forming around the water filter casing and edges of the aquarium interior. I think this was due to overfeeding as I was trying to find out exactly how much to feed them during the day; there was a lot of waste accumulating on the gravel and ammonia quickly rose to 1 mg/L (stress).

Sadly, I just lost two neon tetras, and am in the process of giving the aquarium a deep cleaning. I wonder if anyone know what the best Hardiness (GH), Alkalinity (KH) and pH would be for a 5 gallon freshwater aquarium? Or if anyone knows a good source to find out?

Ok, you are mostly looking at the wrong things here. Don't worry about PH or KH, those are very difficult to control and matter very little unless you are using certain live plants, coral or specialty fish like discus. GH of 0 is concerning, that should not be possible unless you are putting all RO water or something. I've seen fish do fine in GH from 2 to 20.

What appears to be happening here is your tank is not cycled. You need to be monitoring Ammonia (Am), Nitrites (Ni) and Nitrates (Na). Basically, fish poop Am, Beneficial Bacteria (BB) eat the Am and produce Ni, then different BB eat the Ni and poop Na. Ammonia and Nitrites are very toxic to fish... Nitrates much less so. The important question is what type of filter are you using? This is what the BB will grow on. You can cycle a tank with fish in it, but you will need to do frequent water changes and put in ammonia neutralizer (look for a product called "Prime"). If your fish seem to be at the surface struggling to breath it is probably a spike in Ni, an immediate water change will help with this.

What you probably saw when the water got cloudy was a bacterial bloom of the Nitrite eating BB, this is common during a tank cycle and could last a day to a week. Monitoring the Am, Ni & Na is important. If Am or Ni are higher than 0, use prime and/or do water changes. Your tank is cycled when you consistently get readings of Am=0, Ni=0 and Na>0 (test kits are available at most pet shops)... from that point you only need to do water changes when the Na gets over 80-120 (fish dependent)... When you get to that stage, DO NOT CHANGE YOUR FILTER... this is where your BB live and changing it will crash your cycle.

In other words, lots of work in the beginning, but once everything gets settled it becomes easier.

For more info google "ammonia cycle" or "cycling an aquarium"

Best of luck!

 

[Rigatoni]

Ok, you are mostly looking at the wrong things here. Don't worry about PH or KH, those are very difficult to control and matter very little unless you are using certain live plants, coral or specialty fish like discus. GH of 0 is concerning, that should not be possible unless you are putting all RO water or something. I've seen fish do fine in GH from 2 to 20.

What appears to be happening here is your tank is not cycled. You need to be monitoring Ammonia (Am), Nitrites (Ni) and Nitrates (Na). Basically, fish poop Am, Beneficial Bacteria (BB) eat the Am and produce Ni, then different BB eat the Ni and poop Na. Ammonia and Nitrites are very toxic to fish... Nitrates much less so. The important question is what type of filter are you using? This is what the BB will grow on. You can cycle a tank with fish in it, but you will need to do frequent water changes and put in ammonia neutralizer (look for a product called "Prime"). If your fish seem to be at the surface struggling to breath it is probably a spike in Ni, an immediate water change will help with this.

What you probably saw when the water got cloudy was a bacterial bloom of the Nitrite eating BB, this is common during a tank cycle and could last a day to a week. Monitoring the Am, Ni & Na is important. If Am or Ni are higher than 0, use prime and/or do water changes. Your tank is cycled when you consistently get readings of Am=0, Ni=0 and Na>0 (test kits are available at most pet shops)... from that point you only need to do water changes when the Na gets over 80-120 (fish dependent)... When you get to that stage, DO NOT CHANGE YOUR FILTER... this is where your BB live and changing it will crash your cycle.

In other words, lots of work in the beginning, but once everything gets settled it becomes easier.

For more info google "ammonia cycle" or "cycling an aquarium"

Best of luck!

Very helpful, thank you! An in-depth explanation on tank cycling really needs to be included in the instructions when buying new aquariums. It's a good learning experience though.

I already finished doing a deep cleaning before reading the replies, but hopefully some beneficial bacteria are left. I did another test and hardiness is about 75, Nitrite and Ammonia are slightly above 0 (still considered safe), Nitrate is about 0 and chlorine is 0. I may have to restart the cycling process as I replaced all the water, but have a much better idea on what to expect.

 

[chevyontheriver]

I set up a 5 gallon freshwater aquarium last week, and stocked it with 4 different types of fish (7 total).
View attachment 302206

At first the water quality seemed great: the water was clear, the ammonia registered basically naught, and everything else came up as safe when tested.

I noticed Alkalinity (KH) was high (over 300), and pH was about 7 or 8, and Hardiness (GH) was basically 0. I wasn't sure if any of this was anything to worry about as the test strip instructions didn't say, and I couldn't find any definite answers online.

This past weekend, I noticed the water was unusually cloudy, and a swarm of bubbles were forming around the water filter casing and edges of the aquarium interior. I think this was due to overfeeding as I was trying to find out exactly how much to feed them during the day; there was a lot of waste accumulating on the gravel and ammonia quickly rose to 1 mg/L (stress).

Sadly, I just lost two neon tetras, and am in the process of giving the aquarium a deep cleaning. I wonder if anyone know what the best Hardiness (GH), Alkalinity (KH) and pH would be for a 5 gallon freshwater aquarium? Or if anyone knows a good source to find out?

Pay attention to what they are saying about cycling the tank. But there is another consideration. The kind of fish you want. You only mentioned neon tetras but said you had three other kinds. Different fish are native to different lakes or rivers that have their own unique water chemistries. So there is no ideal chemistry for your tank until you decide what kind of fish you want.

Mollies and swordtails like a higher pH, a bit of salt too. Neon tetras like soft water and a bit lower pH. Discus like excessively soft water that is a bit acidic. Discus are consequently difficult, so I am not recommending them. Neons are cool, as are many of the other tetras like cardinals, lemon, black, or any number of other kinds. They are small and active and live a long time. But you will need to keep the water soft and the pH just a bit below 7. Possible, but you will probably not be able to use plain tap water. Many good pet shops sell RO water, and you can mix that judiciously with tap water when you do your water changes.

You will have to do water changes if you are going to make this work. Maybe 10%twice a week. Plan on it.

If soft water seems like a bother, go with mollies or platies or swordtails. They are livebearers and will most likely reproduce for you. Get several and have fun.

 

[topher694]

Very helpful, thank you! An in-depth explanation on tank cycling really needs to be included in the instructions when buying new aquariums. It's a good learning experience though.

I already finished doing a deep cleaning before reading the replies, but hopefully some beneficial bacteria are left. I did another test and hardiness is about 75, Nitrite and Ammonia are slightly above 0 (still considered safe), Nitrate is about 0 and chlorine is 0. I may have to restart the cycling process as I replaced all the water, but have a much better idea on what to expect.

As long as the filter material stays wet your BB should be OK, it just needs time to grow and get into balance. If you want to help jump start it go to a pet store and ask for some BB booster (it stinks but it works)

 

[DragonFox91]

I tried setting up a 5 gallon w/out completely cycling a couple times to no avail earlier this summer. You need ammonia to be ZERO as much as you can. If I were you, I wouldn't do 10% changes but 70% or so & testing the water at least twice a day. It'll be the only way to keep ammonia as close to zero as you can. Might take longer to cycle doing that big of water changes, but ammonia is deadly.

GH, KH, & pH tend to be pretty stable. I wouldn't really worry about those & just test pH once a week or so.

Keep us posted. I'm hoping all your fish make it, but you may lose a couple more.

 

[Rigatoni]

I ended up losing over half my fish, but still have about 3 left. They're doing very well and are quite energetic, and that bacterial bloom the other day has largely subsided. Although, the ammonia level has been about 0.5 over the past 2-3 days. Still considered safe, but I'll change the water tonight.

The water quality seems to have somewhat stabilized by now. But I'm keeping a close eye on it, and have a better idea what to expect, as well as how to respond to large fluctuations in chemistry. Looking forward to eventually replacing the fish I lost, and perhaps getting some new types.

 

[Rigatoni]

Ended up buying small gravel cleaner for my aquarium to help keep it clean, and to aid in water changes. Also took a trip to a local fish store to get ideas for what to buy in the future, once it's been successfully cycled.

I may end up getting different variants of the types I started with, and maybe adding some new ones like dwarf lobsters and snails.

 

[chevyontheriver]

Ended up buying small gravel cleaner for my aquarium to help keep it clean, and to aid in water changes. Also took a trip to a local fish store to get ideas for what to buy in the future, once it's been successfully cycled.

I may end up getting different variants of the types I started with, and maybe adding some new ones like dwarf lobsters and snails.
-uploading pics-

The gravel cleaner is a great tool. I'm presuming you got the simple tube with a hose on the end. Suck out the fish droppings and change some water in the process. Good.

 

[Rigatoni]

The gravel cleaner is a great tool. I'm presuming you got the simple tube with a hose on the end. Suck out the fish droppings and change some water in the process. Good.

Yes sir. It has a catch built in to prevent sucking in the gravel itself, and a pump that makes it much easier to establish a suction. Was only about $7-$8 plus tax.

 

[Rigatoni]

Ammonia has proven to be a major problem though - I've been struggling to keep it even below 0.5. Every morning for the past few days I've noticed a strange multi-colored aurora at the water surface, and ammonia has measured at 1 (stress) for about 2-3 days straight.


I've replaced about 50 to 70% of the water each day that aurora has appeared, and it does go away for awhile. But it eventually comes back. I've tried Tetra SafeStart to help establish beneficial bacteria, but it doesn't appear to be working yet. A worker at the fish store recommended Fritz Complete Water Conditioner instead, so I'm trying that to see if it works. I'm not sure if it's related to the water filter cartridge needing to be changed.

Any ideas or recommendations?

 

[chevyontheriver]

Ammonia has proven to be a major problem though - I've been struggling to keep it even below 0.5. Every morning for the past few days I've noticed a strange multi-colored aurora at the water surface, and ammonia has measured at 1 (stress) for about 2-3 days straight.
View attachment 303018 View attachment 303019

I've replaced about 50 to 70% of the water each day that aurora has appeared, and it does go away for awhile. But it eventually comes back. I've tried Tetra SafeStart to help establish beneficial bacteria, but it doesn't appear to be working yet. A worker at the fish store recommended Fritz Complete Water Conditioner instead, so I'm trying that to see if it works. I'm not sure if it's related to the water filter cartridge needing to be changed.

Any ideas or recommendations?

Just wondering if your water utility merely adds Chlorine or if instead they add Chloramine? Chloramine lasts longer but the amine ends up as Ammonia in the water. Activated carbon removes the Chlorine but the Amine is trickier. Here's how to tell. You contact your water utility and ask them. Here's another way. Get a gallon of distilled water and see if using that for replacement water works better. Caution -- fish cannot live in pure distilled water. They need various ions in the water to live, some bit of hardness in the water. Some like Mollies and Swordtails actually need a dollop of salt (Kosher or rock salt) to thrive.

 

[Rigatoni]

Just wondering if your water utility merely adds Chlorine or if instead they add Chloramine? Chloramine lasts longer but the amine ends up as Ammonia in the water. Activated carbon removes the Chlorine but the Amine is trickier. Here's how to tell. You contact your water utility and ask them. Here's another way. Get a gallon of distilled water and see if using that for replacement water works better. Caution -- fish cannot live in pure distilled water. They need various ions in the water to live, some bit of hardness in the water. Some like Mollies and Swordtails actually need a dollop of salt (Kosher or rock salt) to thrive.

That might be something to check. I don't know if they add Chlorine or Chloramine, just that they add Fluoride. The first few days I changed the aquarium water, I used only filtered water from the fridge - which should have removed any impurities like Chlorine or Fluoride.

Although I found an article that has a few recommendations on what to try: 9 Ways to Lower Ammonia Level in Aquarium and Get Rid of it

 

[chevyontheriver]

That might be something to check. I don't know if they add Chlorine or Chloramine, just that they add Fluoride. The first few days I changed the aquarium water, I used only filtered water from the fridge - which should have removed any impurities like Chlorine or Fluoride.

Although I found an article that has a few recommendations on what to try: 9 Ways to Lower Ammonia Level in Aquarium and Get Rid of it

Fluoride is in all municipal water.

The fridge water might be an improvement. Never considered that one.

Good article.