Low KH water from tap, no KH in freshwater tank

[Pompous_Oscar]

I recently discovered the importance of KH for buffering purposes. I could not figure out why my 7.0-ish water from the tap was becoming closer to 6.0 in the aquarium. 

Once I received the test strips from this site in the mail, I discovered the KH in my tank is 0. (ph around 6, 0 nitrite, 10-20 nitrate) It comes out of the faucet at around 25 KH. However, I feel the ph swings are stressing my community tank out. Especially my Oscar.

Some suggest alkaline/acid buffer, some suggest things like crushed coral. Any ideas? I'd prefer not to have too high of a PH since it is a community tank. Something natural and low maintenance would be terrific.

The 125 gallon tank consists of 1 oscar, 5 silver dollars, and 1 featherfin catfish. 2 FX6 and 1 Tidal 110. The sand is Stoney River and is supposed to be PH neutral. I also have a pothos plant in hydration leca. 

 

Edited June 30 by Pompous_Oscar
forgot to mention type of plant.

[Fish Folk]

Just add KH buffer powder, or Alkaline Buffer. Equilibrium might help.

If you can, add tap water to several 5-gal buckets with air-stones. Let that rest / run for 72-hrs. That should help settle your tap water chemistry somewhat. Add your powder to that. Then water change from there.

Another option: go for Discus. They love soft water…

[Tony s]

On 6/30/2024 at 6:21 PM, Pompous_Oscar said:

Some suggest alkaline/acid buffer

I think this is a safe way to go. You can also add baking soda to the water. Both products won’t raise your gh any. You’ll have to use them every time you change water though. With the 2 buffers you can actually target a certain ph when used together. You can use equilibrium to add gh back into the tank as well. Up to the level you desire. The problem with some of the more natural additives is that there is not a lot of control. They absorb up to the point they can’t absorb anymore. Possibly way higher than you actually want.

[Tony s]

Your fish should do fine in your soft water. Honestly, with that water you could do some very sensitive species. Like discus, rams, appistos, or even wild caught South American species.  You can get around your kh issues and do smaller, more frequent water changes. Keeping your nitrates and organic content at super low levels. 

[Pepere]

On 6/30/2024 at 8:54 PM, Fish Folk said:

Just add KH buffer powder, or Alkaline Buffer. Equilibrium might help.

In my experience Equilibrium has no affect on KH levels.

 

I use Seachem Alkalinity Buffer. It has nice measurable results.  1 teaspoon added to 20 gallons raises KH 2.8 degrees and I believe it is Sodium Free unlike baking soda.  It is significantly more expensive than baking soda though, but I really dont need to use it often or much.

My tap water has 1 degree KH and weekly 50% water changes do the lions share for me.

I always test PH after a water change before adding Easy Green as I front load Easy Green to get to30 ppm nitrates after a water change as the iron in Easy Green binds up if ph is too high.  Yesterday after water change, ph was 6.0 or less.  This led me to test for KH which was under 1 degree.  Ie, 1 drop of kh reagent and the test sample was still yellow.  I added about 3/4 a teaspoon to my 29 gallon tank and KH was 2 degrees and ph raised to 6.8.

 

 

 

 

[quikv6]

I agree with Tony S, in that your fish would thrive in soft water. You would want to keep hardness to a minimum for South Americans. Being you have an Oscar in a 75, you should be doing frequent waterchanges regardless to keep nitrates down. They are generally pretty messy, and produce alot of waste.

You could also leave a very small media bag with crushed coral in that Tidal filter. You'd want just enough to give you a bit of KH, without really adding much to GH levels.

[Rube_Goldfish]

Bear in mind, too, that healthy waterways can swing a full pH point over the course of a 24 hour period as plants transpire, and fish deal with that just fine. Is the oscar visibly stressed?

[face]

What makes you think the fish are being stressed by the ph change? Any symptoms?

I had an Oscar for a long time ph never effected her and my water goes from 8 to 6.5 ph after resting for a bit because my water company adds something to the water so it doesn’t erode the pipes I have no detectable kh in my water at all 

[Pompous_Oscar]

On 7/1/2024 at 6:27 AM, quikv6 said:

I agree with Tony S, in that your fish would thrive in soft water. You would want to keep hardness to a minimum for South Americans. Being you have an Oscar in a 75, you should be doing frequent waterchanges regardless to keep nitrates down. They are generally pretty messy, and produce alot of waste.

You could also leave a very small media bag with crushed coral in that Tidal filter. You'd want just enough to give you a bit of KH, without really adding much to GH levels.

Thanks for your response. It is a 125 gallon if that makes much of a difference.

About how much crushed coral do you think would do the trick?

Edited July 1 by Pompous_Oscar
add question regarding coral

[Pompous_Oscar]

On 7/1/2024 at 9:47 AM, face said:

What makes you think the fish are being stressed by the ph change? Any symptoms?

I had an Oscar for a long time ph never effected her and my water goes from 8 to 6.5 ph after resting for a bit because my water company adds something to the water so it doesn’t erode the pipes I have no detectable kh in my water at all 

I had a Green Severum that was quite the tank bully which seemed to stress the Oscar. Once she developed HLLE, I removed the Severum. About a month ago I medicated the tank with Fritz Prazacleanse. This caused a bit of a cycle crash. 

Here are some pics of what the Oscar was doing off and on for about two weeks.

 

o weeks.

[Rube_Goldfish]

On 7/1/2024 at 4:00 PM, Pompous_Oscar said:

I had a Green Severum that was quite the tank bully which seemed to stress the Oscar. Once she developed HLLE, I removed the Severum. About a month ago I medicated the tank with Fritz Prazacleanse. This caused a bit of a cycle crash. 

Here are some pics of what the Oscar was doing off and on for about two weeks.

 

o weeks.

Is the oscar still laying on the substrate like that? Did any of the other fish ever lay down like that? You said you had a cycle crash: did it rebound? My immediate thought is that to think that the oscar laying down and the cycle crash were related, rather than the pH, but you know oscars better than I do.

Edited to add: the ACO care guide on oscars says a pH range of 6-8.

[Pompous_Oscar]

On 7/1/2024 at 4:06 PM, Rube_Goldfish said:

Is the oscar still laying on the substrate like that? Did any of the other fish ever lay down like that? You said you had a cycle crash: did it rebound? My immediate thought is that to think that the oscar laying down and the cycle crash were related, rather than the pH, but you know oscars better than I do.

No, those pics were from a couple weeks ago. The cycle rebounded. I also changed out from a bubble wall to two large air stones. None of the fish have been having much in the way of an appetite since this all occurred. 

[Rube_Goldfish]

On 7/1/2024 at 4:09 PM, Pompous_Oscar said:

No, those pics were from a couple weeks ago. The cycle rebounded. I also changed out from a bubble wall to two large air stones. None of the fish have been having much in the way of an appetite since this all occurred. 

Then I think we're pretty well passed my level of knowledge. @Colu, anything jump out at you?

[Colu]

Typical you want to add one pound of crushed coral per 10 gallons to increase your KH and GH you can add it to your filter in a media bag or add it to the substrate I would add 1 pound  per 50  gallons just to get a slight increase in your KH to prevent pH swings little more information would be helpful how often do you water change what are you feeding and how often how long has the food been open any rapid breathing hanging out near the surface lethargy flashing spitting food out sunken belly white stringy poop how is the oscar hole in the head doing after treatment have introduced any new fish into the tank that could have bought in disease @Pompous_Oscar

[quikv6]

HITH seems to be common with Oscars. Many far more knowedgable than I have attributed it to either excess hardness directly, or indirectly, the bacteria that can cause it being more present in waters with increased mineral content...ie: excess hardness. Some also say Nitrates may play a role. I try to keep my Nitrates under 10ppm in my Oscar tank.

Metroplex seems to be the go-to to treat HITH.

I have similar water, with PH of around 6.7 out of the tap, and low KH. I wanted to increase KH a bit, while doing my best not to increase GH much. I just have a small media bag (maybe 1/2 pound) in my HOB on that tank....with a spritz of coral in the substrate. It nudged KH up (and GH just a tad) but it was just enough to stabilize PH.

Consistency is key....and 6.0-7.0 range should actually be close to ideal for the O. I would not keep South Americans at 8.0 with high hardness, regardless of the range stated within some guides. Just my opinion, though I know many have had success with it.

[Pompous_Oscar]

On 7/1/2024 at 7:17 PM, Colu said:

Typical you want to add one pound of crushed coral per 10 gallons to increase your KH and GH you can add it to your filter in a media bag or add it to the substrate I would add 1 pound  per 50  gallons just to get a slight increase in your KH to prevent pH swings little more information would be helpful how often do you water change what are you feeding and how often how long has the food been open any rapid breathing hanging out near the surface lethargy flashing spitting food out sunken belly white stringy poop how is the oscar hole in the head doing after treatment have introduced any new fish into the tank that could have bought in disease @Pompous_Oscar

@Colu I usually do about 40% or so each week. No new fish in over a year. About a month ago, I did remove the Green severum that was bullying all other fish (except the Oscar). I haven't seen any surface dwelling. There was some rapid breathing from the silver dollars during the cycle crash, but not since. No stringy white poop either.

On 7/1/2024 at 8:23 PM, quikv6 said:

HITH seems to be common with Oscars. Many far more knowedgable than I have attributed it to either excess hardness directly, or indirectly, the bacteria that can cause it being more present in waters with increased mineral content...ie: excess hardness. Some also say Nitrates may play a role. I try to keep my Nitrates under 10ppm in my Oscar tank.

Metroplex seems to be the go-to to treat HITH.

I have similar water, with PH of around 6.7 out of the tap, and low KH. I wanted to increase KH a bit, while doing my best not to increase GH much. I just have a small media bag (maybe 1/2 pound) in my HOB on that tank....with a spritz of coral in the substrate. It nudged KH up (and GH just a tad) but it was just enough to stabilize PH.

Consistency is key....and 6.0-7.0 range should actually be close to ideal for the O. I would not keep South Americans at 8.0 with high hardness, regardless of the range stated within some guides. Just my opinion, though I know many have had success with it.

@quikv6 I have added some metroplex/focus/garlic guard to some frozen beef heart. She ate a few pieces of it within the last week or so.

I would like to increase the KH without too much GH change. Would just like to avoid dramatic PH swings as much as possible.

What size is the tank that you added the 1/2 pound to?

Edited July 2 by Pompous_Oscar

[Tony s]

On 7/1/2024 at 4:00 PM, Pompous_Oscar said:

Here are some pics of what the Oscar was doing off and on for about two weeks.

Apparently Oscars will do that from time to time. John Hudson, kgtropicals, says his oscar will do this after water changes. His oscar get ticked off that his tank has been disturbed. An intelligent animal just throwing a fit. Not saying that’s what yours is doing, but it’s a possibility.

[Tony s]

On 7/1/2024 at 8:23 PM, quikv6 said:

HITH seems to be common with Oscars. Many far more knowedgable than I have attributed it to either excess hardness directly, or indirectly, the bacteria that can cause it being more present in waters with increased mineral content...ie: excess hardness. Some also say Nitrates may play a role. I try to keep my Nitrates under 10ppm in my Oscar tank

I don’t believe hith or hlle (head and lateral line erosion) has a lot to do with hardness. Oscars are very commonly kept in harder water with no ill affect. Most of the US has hard water. It has more to do with excessive amounts of organic material in the water. Your nitrates can be fine, but you can still have a great deal of organics fouling the water. And oscars generate a ton of organic. Feeding oscars a diet of poor quality or inappropriate materials can also aid hlle. 

[Colu]

I would look at the diet oscar are omnivores that like a bit  more protein in there diet they will eat fruit nuts insects plant matter small fish  in wild  I wouldn't recommend feeding them beef heart I would feed a good quality cichlid pellet such hikari cichlid gold extreme big fella pellets repashy super green has a high percentage of algae frozen or live foods such as mysis shrimp black worms blood worms piece of tilapia 

[quikv6]

My 1/2 pound media bag is in a 180 gallon tank. It does the trick. My Oscar also likes the Kensfish food sticks that has Metronidazole in it. That may be a better option than beefheart. But it is a good sign that he's eating.

I did have my O in a 125 before, and noticed much better behavior for him when I bumped him to a 180. I change about 80 percent per week, and he really seems to perk up after waterchanges. O's are really big, messy fish, and seem to benefit from large water changes..ie: clean water

[face]

I agree with Colu clear water and a good diet is the key to getting rid of HITH beef heart is very fatty and fatty liver is t thing with them Oscars also tend to be vitamin c deficient so some fruit if he will eat it if not a vitamin supplement wouldn’t hurt 

I will say to it likely won’t fully heal scars will probably be visible for the rest of his life and he will be more susceptible to getting it again to 

and just to add the laying on the ground is like a kid crying it could mean there hurt or it could just be something not important…I know someone that had one sit like that all day because he changed a picture across from the tank lol but a lack of appetite is worrying