Do I need to harden my water?

[Lorazoo]

I am setting up a 125 planted tank. I have had the plants in it for a couple of weeks and am setting up the CO2 next week, as soon as I get it in the mail. Anyway, right now, according to my tests my pH is at 7.0 and my dKh is at 5. Do I need to raise this before I add CO2?

I want to add cherry shrimp soon followed slowly by algae eaters, catfish, and a variety of tetras, barbs, kribensis, rainbowfish, etc. Basically a peaceful community aquarium.

What do you think? Do I need to harden it a little bit? I am worried the pH will go down too mauch after CO2 addition.

[mrgrudge]

Higher KH will increase the buffering capacity of the water which makes it harder for the PH to change, making it more stable.

[dominuslive]

Well, most of what you have like slightly acidic and soft water, I would keep your KH where it is, and play with the co2 till you find out what amount of bubbles you need to get a desired affect. I would say 5-6 bpsshould be good in that tank, and might bring your ph down to 6.5-6.8. Which the tetras and cats would like. Remember to set it up with your lights, and some say to areate at night, but I am not sure that is logical, since o2 raises ph, and co2 lowers it. Just at least have it go off at night since the plants will release co2 at night. Better yet, have an automatic ph meter control it, and it will shut off when the co2 drops the ph too much.

[dominuslive]

Well, most of what you have like slightly acidic and soft water, I would keep your KH where it is, and play with the co2 till you find out what amount of bubbles you need to get a desired affect. I would say 5-6 bpsshould be good in that tank, and might bring your ph down to 6.5-6.8. Which the tetras and cats would like. Remember to set it up with your lights, and some say to areate at night, but I am not sure that is logical, since o2 raises ph, and co2 lowers it. Just at least have it go off at night since the plants will release co2 at night. Better yet, have an automatic ph meter control it, and it will shut off when the co2 drops the ph too much.


I have a KH of 7, I co2, ph remains at 7.2. I have to add peat to bring it down more

[RTR]

Fish don't"read" ph. They do read osmolarity, osmotic pressure.

At a current pH of 7.0, you would not be adding enoght CO2 to do the plants any good at all at pH 6.8, and at 6.5 only only if the light is low to barely maderate. What di you plan for lighting? That would be the deciding factor. At high ligh levels you need to push the pH down about a log, and pH 6.0 is a but low for me. I'd want KH and pH at about 7.5 without CO2, about pH 6.6 with.

[Lorazoo]

I have the lights set up as 2WPG. I was thinking of doing more, but this may be suffiecient, so I was going to see how the plants did after setting up the CO2. As a side note, I have one of the Turbo Red Sea CO2 generators hooked up now. According to the CO2 calcs it says I have 15ppm CO2 in the tank now with the hardness at 5 and pH at 7. I cant believe that something supposed to be for tanks up to 40 gallons would produce so much CO2 in my 125.

I was worried about it becoming a bit too acidic too. I will have the pH monitor connected to the regulator so my pH wont crash.

But, if I did want to raise hardness I have heard you can add baking soda? How much would I add to a tank of this size?

[Ransom]

with the hardness at 5 and pH at 7. I cant believe that something supposed to be for tanks up to 40 gallons would produce so much CO2 in my 125.

In your first post, before you started CO2, you also said the hardness was 5 and the pH was 7. This makes me wonder if you had already added something to alter the pH of your tank. The calculations/charts about KH, PH and CO2 are meaningless if you have added any buffers or acids to the tank.

[Lorazoo]

i have added no buffers or acids to the tank. The small CO2 Turbo has been on since the first few days. I had measured the pH and it was about 7.3, but I didnt have the hardness test yet. I have the Red Sea Co2 measurer and it is still telling me I dont have a high enough level of CO2. That is why I deciided to go for the tank. So, then I got the hardness kit in the mail and did all of my tests and that is where i got the pH of 7 and hardness of 5.

I am still unsure if I should raise the hardness before I hook up the CO2 tank and if I need to how to do it.

That is why I came on here, hoping to get some help.

[daveedka]

Typically a dKh of 5 is plenty, but as has been indicated a dKh of 5 should put your original pH a bit higher. Take out some tank water and let it sit ovenight in a shallow bowl or plate. then re-test.
Aslo remeber that As mentioned your baseline pH with enough co2 would be the primary concern. Raise your dKH to accomodate the end result you are after.

You will also want to look at Gh or more importanty calcium levels for the shrimp. If your Kh is naturally near 5 I would guess that your GH is adequate for the shrimp BUT Municiple water often strays dramatically from natural norms, so I would test before trusting

[Lorazoo]

so if i decide to raise my dkH how would i do that? and how do i test for calcium levels?

[twig]

I think co2 will help even in a low light condition... (shrug)

People on the forums said not to bother that i wouldn't see a difference but since i installed my co2 last week my anubias has put out three new leaves and my hydro are growing like crazy :o

i have a 20g with 15watts

[daveedka]

Co2 will help in any light, In high light it is a requirement and levels need to be much higher.

There are several ways to Raise Kh and buffer a tank. Probably the easiest, most stable, and most common is to add a bag of Crushed coral to your fiter.

Calcium test kits are avaialble, but in most cases a view of your drinking water analysis will tell you enough. Additionally GH numbers will reveal a good bit as GH trsts for Ca++ and Mg++ in the water.

Dave

[beviking]

Ah ha! Now I see the confusion Lora. In case you didn't "get" what RTR was saying, ideally for a high light tank, you want your pH to drop by 1 full "pH point". This would mean there would be enough CO2 for the plants to grow their best, provided there were ample nutrients to allow it. If your situation is different (2wpg is NOT high light) then you don't need that much. I would say for your case, .4-.6 drop in pH would be sufficient, BUT it may not be.

As Dave said, you need to establish your original pH. If it is 7.3, then you only need to come down to 6.6-6.8. Also as Dave said (twig too), CO2 will help in any light, and even some is better than none.

I won't repeat what else Dave (good advice btw!) has already said, but the email with my GH was a hint at that ;)

-Bill

[Lorazoo]

Well, thanks again guys. It is so nice to have people to help me out with these things. I guess my pH is almost there. I will probably set my pH meter for 6.6 when i set it up with the regulator. I like the crushed coral idea in the filter. I think I will have to look for some of that. I figure it cant hurt to raise the kH a little since its only 5 right now. From what ive read, the fish like it a bit harder anyway.

[Lorazoo]

Another quick question. Right now I am using my pH and dKh to measure my CO2 levels. If I add the crushed coral to increase dKh, will this affect my ability to calculate CO2?

[RTR]

No, the crushed corral will slowly increase the KH a bit, or help keep it stable, so you will still have to use the KH test to see where you are at the moment, but it dies not distort results. The difference in the KH is just the new or current baseline for what the pH would be eithout CO2. You have to test for KH with each measure anyway, as KH is normally used by tank biological processes.