# Help with PH



## Snydaleid (Apr 12, 2008)

PH out of the tap is 8.0
My setup with peat moss under the substrate and some wood has a PH of 6.6
I just started my DIY CO2 and now I'm at 6.0.
After a ~30% water change it's up to 6.4 for a while.

Is the PH at 6.0 going to be a problem for my plants? What about for fish that like acitic water? Is this going to be too acitic for them? Is there anything I should do to bring up the PH?


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## ngb2322 (Apr 9, 2008)

What fish and plants are you keeping? What are some other tank parameters, i.e. nitrate, GH, KH, etc? I keep my pH around 6.0-6.2 with no problems and I keep killifish, flame tetras, corys, bushy plecs, clown plecs, and white clouds. Most freshwater plants actually prefer neutral to slightly acidic water, so you should be okay. Also, despite what you read, many fish can adapt to different water than they are "supposed" to be in, as long as the change is not too drastic or sudden.


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## cfreeman (Mar 19, 2008)

What is your KH in the tank? This will affect how low your pH level needs to be to maintain favorable CO2 levels. That said, I do not believe that a pH of 6.0 will be a problem for most plants. I hope this is helpful.


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## Snydaleid (Apr 12, 2008)

Nitrite 1 ppm
Amonia was clear. It says yellow is 0ppm. what is clear?
Nitrate 0ppm

Reading the GH and KH was kinda difficult. It's a lil difficlut to read around 5 different languages ya know. But this is what I got out of it.

For GH put a drop in and mix it up until the color changes. 8 drops total. Multiply that by 20. So GH is 160.

For KH multiply the drops by 10. 5 drops. so that's 50. 

There were like 5 or so calculations on the back of the booklet but with little explination and 5 or so languages to read around. So I didn't really understand that part. So if you could help me out on that I'd appreciate it.

Right now I have jungle vals and Hygro corymbosa in there right now. I'd like to keep S. American fish in there but don't have any right now. Just have my GF blackmoor in there right now.


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## Diana K (Dec 20, 2007)

GH is a measure of Calcium and Magnesium in the water. These are plant fertilizers.
KH is also called alkalinity, and Carbonates. It is a measure of carbonates in the water. Cabonates, pH and CO2 levels are linked so that in general when KH is high, then pH is high and CO2 is low. If KH is low, pH is generally low, and CO2 may be present.

GH and KH are measured in a couple of ways. The most common in aquariums is in German degrees of hardness or in ppm. 1 degree = 17.9 ppm. 
It looks like your kit is reading in ppm. 
GH of 160 ppm is rather hard water, but is not a problem. Calcium and magnesium are required nutrients. 
KH of 50 is rather soft water, and the pH can change very easily in such water. Be careful adding CO2 to this tank, as you have seen the pH can crash quite easily. 

Fish prefer a stable TDS (Total Disolved Solids- So Google it!) which can sort of be monitored with GH and KH, but is really not the same thing. KH is pretty closely related to pH most of the time, but not always. Monitoring the pH and keeping it stable might be the only way there was many years ago to keep the fish happy, but as you can see it is only very loosely connected to the measurement you ought to be monitoring for the fish. 

Low pH:
Nitrifying bacteria tend to thrive with a pH about 7.5, with a range of around 6.5-8. At 6 (The pH you see in your tank) the nitrifying bacteria will not function well, so you may see ammonia and nitrite, unless the plants remove them. 
At low pH ammonia is in its less toxic form (NH4+)
Plants need certain minerals and other elements that combine chemically in different ways depending on the pH of the substrate. Most nutrients are most available at something close to neutral. A range of about 6.5 to 7.5 seems optimal. 
Low pH is loosely linked to soft water, that often is lacking in minerals. In your case the GH is high enough that there may well be enough minerals present for the plants and fish, but are those minerals available in a way that the plants can use them?

Low KH:
The balance between carbonates and CO2 will tend to stabilize the pH. With little or no carbonates the pH in the water can change very easily, from showing 8 out of the tap to crashing to 6 in the tank. I would add some carbonates until you get a reading of around 3-4 degrees (a bit closer to 55-70 ppm). This should stabilize the pH in the mid 6s. One source of carbonates is baking soda. I have found that 1 teaspoon of baking soda added to a 29 (American) gallon tank will raise the KH from 0 degrees to 2 degrees and raise the pH from 6 to 6.4

GH:
Water that travels through the soil, rocks across the land or underground will pick up whatever minerals can be dissolved in the water. Most often this includes calcium and magnesium carbonates, but is certainly not limited to these minerals. Water that has any of these from natural sources usually has other minerals that we do not commonly monitor. Many of these other minerals are also plant nutrients. 
Water that has the GH artificially altered may or may not have all the minerals required for plants and fish to be healthy. For example, some people start with reverse osmosis water and add just Epsom salt to the water so that the GH will read at a certain level. Reverse osmosis removes almost all the minerals in the water, and Epsom salt just adds magnesium. This is not healthy water for the plants, fish or invertebrates; it lacks calcium and many other minerals.


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## cfreeman (Mar 19, 2008)

The ammonia test often shows clear. Sometimes you have to look through the top of the test tube to notice the yellow color. Anyway, clear is good, it means that there is no detectable ammonia. It sounds like the tank is still establishing the nitrogen cycle, judging by the nitrite amount. I would keep an eye on this.

Anyway, on to your question. Looking at the CO2 chart that I have, with a pH of 6.4 and KH of 50, it looks like you have CO2 at the top of the optimal range, about 33ppm. As with many topics in this hobby, there are a lot of opinions. I run my tanks at about 30 ppm CO2 and the plants grow well and the fish seem happy.

Here is a link to a calculator which will help you to calculate your CO2. It is on Chuck's planted aquarium pages, which I have found to be helpful references:

http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

When your pH level drops to 6, your KH will also change, so you just need to input the new values in the calculator to make sure you have sufficient (but not too much) CO2. It sounds like overall you have favorable values, so I would let everything run and see how it goes. Keep a close eye on ammonium and nitrite to make sure they don't elevate. Sometimes on new tanks I have checked these twice daily, just to be sure.

I hope you find this helpful. If I have been unclear in any explanations, kindly let me know and I will try to clarify.


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## Squawkbert (Jan 3, 2007)

AFAIK:
1) pH drop due to the addition of CO2 is not harmful
2) CO2 addition does not alter your KH
2a) Altering your GH is not a reason to alter your rate of CO2 delivery
3) A drop checker is a much better way to monitor your CO2 than using KH & pH charts as they assume that your KH reading is strictly a function of carbonate hardness (which, in an aquarium, it isn't).


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## Snydaleid (Apr 12, 2008)

Thanks Diana for all that great info. I'll try adding some baking soda tonight and see where that takes me. 

cfreeman 
It's a 37 gallon with only 1 fish in it. Has been up for 2 weeks now so it will need more time to cycle. I've been doing quite a few water changes to get rid of the brown water. It's all cleared up now so I'll slow down on that.


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## Snydaleid (Apr 12, 2008)

Ok I added some baking soda. I now have a pH of 6.4 and my KH at 100ppm.

I don't feel that the chart is very accurate. It assumes that the pH is dropped by the CO2 being added to the water. I had a pH of 6.6 before adding any CO2. According to the chart I was already at an optimal level of CO2 without injecting any. Also, according to the chart I was at a harmful level of CO2 for my fish after I started injecting. My lil fish wasn't gasping for air at the surface. He was zooming around the tank happly like always.


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## cfreeman (Mar 19, 2008)

I think that your observations back up Squawkbert's comment about drop checkers being more accurate indicators of CO2 content than the KH/pH charts. If you get a drop checker and then use 4 degree (71 ppm) KH solution in the drop checker, the solution will be green when you have 30 ppm CO2 in the aquarium. It is also nice to have a readily visible indicator of CO2. It saves you from doing the titration and working with cross reference charts!


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## Snydaleid (Apr 12, 2008)

I've been meaning to get back here to post this update.


The tank was setup and running for 2 weeks without any algae. After putting in the baking soda I see it everywhere.

Perhaps raising the pH put it to where algae can grow?


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