Please help: New to the pH/KH/CO2 balance

3141 Views 13 Replies 7 Participants Last post by Ceveji, May 27, 2014

Ceveji

Discussion Starter · May 15, 2014 (Edited)

Hello!

I just set up a CO2 injection (canister) system on my 60g freshwater. I set up the pH controller yesterday and ordered a drop checker (don't have it yet). In the meanwhile, I've been pulling my hair out trying to keep my CO2 levels in the safe "green" range of that KH/pH chart based on the KH readings I've been taking & the pH controller measurements.

The issue is that my pH is being pulled down by something in the tank (tap is at 7.5 or so) and I also have very low (barely a degree) of KH. Can someone confirm for me that the Tetra brand KH test uses 2 DROPS per 1 DEGREE (and not 1 drop per degree like other tests)? Also I've been adding baking soda (just a half a tsp) to try and keep the KH up and the CO2 in the safe range. It seems to make the water CLOUDY. Is there something I'm doing wrong? Will I eternally have to battle to keep the KH up, I wonder? Why is my KH so low in the first place?

Also, I've read that either crushed coral or baked egg shells can be put in the filter to raise KH (or is it pH). Please advise... Should I crush the egg shells and stick them in a little pouch or...? Where can I find crushed coral? Which is better?

So many questions...

Thank you for enduring my naivete!
Best, C :icon_surp

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Zorfox

· #2 · May 15, 2014

I would leave your KH alone. Use whatever your tap water provides. Quit pulling your hair out trying to target a number on a chart. Simply ignore your PH and KH for now. Increase your bubble rate a little every couple of days. Do this when you have time to watch your fish. When you see signs of distress such as gasping at the surface, crowding into one spot, lethargy etc. return the bubble rate to the last setting. That will be your maximum CO2 level for your tank. NOW you can look at your PH. Forget trying to use a lot of gadgets and calculations when dialing in CO2. The best gauge you have for determining CO2 levels are swimming in your tank.

I have never used the Tetra brand KH test so I can't comment.

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Diana

· #3 · May 17, 2014

Coral sand is available in aquarium stores. It is used as a substrate in marine tanks. Entirely safe in fresh water tanks, too.
Limestone and related minerals (Dolomite, Calcite and other names) will also do this. Large chunks sitting in the tank are slow to alter the water parameters. Fine sand sized particles either as substrate or in the filter (in a bag) will have a much faster effect.
Oyster shell grit sold for caged birds is another material with pretty much the same properties.

Get one of those materials in a small amount.
Put it in a nylon stocking (I cut up knee his, and get 2 bags for a large tank, or 3 bags for a small tank out of one stocking).
Put this in the filter and monitor the GH, KH and pH.
All these materials are mostly calcium carbonates and magnesium carbonates. As they dissolve in water they add calcium and magnesium (GH) and carbonates (KH) to the water.
As the KH rises the pH generally rises, though when the KH is still so low other things in the water can control it. (organic matter, CO2)

You could add baking soda (as you are doing). I found it clouds the water only for a few minutes to an hour, then the water is clear.
Potassium bicarbonate is another option. You would use less of it, but it also will raise the KH.

When I want to do this, I make it a 2-part job:
1) Prepare water for water changes with the GH, KH and TDS that I want. Usually having the right KH means the pH will be in the right range.
2) If something in the tank is removing these, and the GH, KH or TDS is dropping, then add corrective materials through the week as needed.

GH- Adding GH booster can raise the GH. This does nothing about the KH. Seachem Equilibrium is one such product.

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jeffkrol

· #4 · May 17, 2014

Diana said:
Coral sand is available in aquarium stores. It is used as a substrate in marine tanks. Entirely safe in fresh water tanks, too.
Limestone and related minerals (Dolomite, Calcite and other names) will also do this. Large chunks sitting in the tank are slow to alter the water parameters. Fine sand sized particles either as substrate or in the filter (in a bag) will have a much faster effect.
Oyster shell grit sold for caged birds is another material with pretty much the same properties.

Get one of those materials in a small amount.
Put it in a nylon stocking (I cut up knee his, and get 2 bags for a large tank, or 3 bags for a small tank out of one stocking).
Put this in the filter and monitor the GH, KH and pH.
All these materials are mostly calcium carbonates and magnesium carbonates. As they dissolve in water they add calcium and magnesium (GH) and carbonates (KH) to the water.
As the KH rises the pH generally rises, though when the KH is still so low other things in the water can control it. (organic matter, CO2)

You could add baking soda (as you are doing). I found it clouds the water only for a few minutes to an hour, then the water is clear.
Potassium bicarbonate is another option. You would use less of it, but it also will raise the KH.

When I want to do this, I make it a 2-part job:
1) Prepare water for water changes with the GH, KH and TDS that I want. Usually having the right KH means the pH will be in the right range.
2) If something in the tank is removing these, and the GH, KH or TDS is dropping, then add corrective materials through the week as needed.

GH- Adding GH booster can raise the GH. This does nothing about the KH. Seachem Equilibrium is one such product.

what about using calcium carbonate "reptarium" sand.. just noticed a bag at Wally world..

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Diana

· #5 · May 18, 2014

I'll bet it would do the same thing.
If it ONLY added calcium, no magnesium (use a fresh water calcium test and research the mathematical formula to calculate Mg) then you might want to use Epsom salt to add magnesium.

Plants use calcium and magnesium in a ratio of about 4 parts Ca to 1 part Mg. The ratio does not have to be perfect, but both minerals need to be present.

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Aqguy

· #6 · May 18, 2014

With a low kh you will have more bounce in your reading ,if you have a controller set your ph to like 6.8 to 7.0 and keep your bubble count down if the ph does not go down then very slowly increase your bubble count.
I let mine run 24/7 ph ph is always 6.8 24/7 that puts me at 30 ppm on the chart .
So people here swear by Turing it off at night ,but I like mine steady.

Don't tweak it to much or your reading will bounce.
You should set your water parameters only during water changes , example to raise kh with baking soda .
Your most likely trying to hard right now and also need to move slowly over a couple of days to let your tank balance it self.

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Ceveji

Discussion Starter · #7 · May 18, 2014

Thanks everyone! I relaxed a bit (after putting a tsp of baking soda in when I wrote the post a couple days ago) and now it seems like the sodium bicarbonate is doing its buffering job to keep the pH stable, more or less, between 6.5-6.9 (I set pH controller at 6.5).

Last night I also set up a drop checker in the tank. Oddly, this morning it's still blue... Hmm. Not enough CO2 right? But at the same time I noticed the discus pump their gills a bit. Any thoughts on keeping fish AND plants happy?

I've got a feeling that my real limiting factor in this whole equation is my light actually. Is one of those aquatic plant LED's from Marineland going to cut it? (Over a 60g that's 36" wide and 24" tall)

Thanks!!

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Diana

· #8 · May 19, 2014

What is the GH in the tap water and in the tank?
Do you need to add Ca or Mg?

If all you want to do is raise the KH, then use a material that does not have calcium or magnesium in it.
If you want to raise the GH as well as the KH, then calcium carbonate, magnesium carbonate and the other materials discussed above will do both.

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Ceveji

Discussion Starter · #9 · May 20, 2014 (Edited)

Hmm. Drop checker still a dark bluish-green. Mostly still the same color as when I set it up. Yet pH is down at 6.3. What should I set the pH controller at for discus, 6.4? The sodium bicarbonate seems to last about a week before the pH comes down again... I'm trying to minimize the pH swings because the discus are acting funny (hiding)...

Hi Diana: Uh-oh, I'm afraid I don't know how to answer those questions. Could you advise? I've been adding micronutrients 1x week. Would Ca & Mg be included there? As per General Hardness (which I had to google), I don't know! What is the relationship between KH and GH? Thanks

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Zorfox

· #10 · May 20, 2014

Ceveji said:
Hmm. Drop checker still a dark bluish-green. Mostly still the same color as when I set it up. Yet pH is down at 6.3. What should I set the pH controller at for discus, 6.4? The sodium bicarbonate seems to last about a week before the pH comes down again... I'm trying to minimize the pH swings because the discus are acting funny (hiding)...

I would try reducing the CO2 level. Set the PH meter higher NOT lower. The change in behavior is most likely a reaction to elevated CO2 levels.

Did you use 4dKH water in your drop checker? Many come with instructions to use tank water. This is completely wrong. It has to be water with a dKH of 4.

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Ceveji

Discussion Starter · #11 · May 23, 2014

Hi everyone,

So I've figured out that the discus really don't do well with the "golden" 30ppm figure of CO2. Does anyone who keeps discus and has a planted tank know what their ideal/safe/happy range would be for CO2 in ppm?

Also, I was able to find some crushed coral and place it in a nylon bag in my filter. How much effect can this really have on the KH? My KH still seems no higher than 2 degrees or so... Should I just keep dosing sodium bicarbonate (aka baking soda) every couple days?

Thanks! C

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jrman83

· #12 · May 24, 2014

There are calculators on the net that tell you how much effect coral will have on your kh as well as ph. It will drive your ph up just as the baking soda did. You do not need to add both if the coral is working for you.

Sent with my Samsung S4 via Tapatalk

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Hoppy

· #13 · May 25, 2014

You have discus, and they don't really like high light. They also prefer low KH to very high KH. But, you only need to push the CO2 high if you have high light. So, perhaps you have more light than you should have. I don't know how much light you have. Someone who knows discus should join in the discussion, or you can PM discuspaul.

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Ceveji

Discussion Starter · #14 · May 27, 2014

Hi again,

Still struggling here. So I've got a small bag of crushed coral in the filter. And yet, yesterday I changed about 60% of the water (pH was at 7.1) and when I was done the pH was at 7.0. Then about 6 hours later, 6.5! Then this morning 6.1! Aaaaaaah! What is going on with my tap water that it comes in at 7.5 then sinks more than a full pH degree in 12 hours? Should I put it in WITH baking soda? Will aging help - if so, why? Is this terrible for my fish? They're happily swimming around (the discus), except the German ram, who's been up at the top since last night...

Whoever knows - please help!

Maybe I should just change my substrate to crushed coral??!!

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