API KH Test

[fddlss]

Hi guys,

I finished cycling my tank less than a week ago, no fish yet, and I tested KH for the first time, today. It takes 3 drops to change the color from light blue to a very soft yellow. Should I add more drops until it turns bright yellow? or it doesn't matter what tone of yellow it is? If that's the case my water has a KH of 3 dKH, which I think it's low if I'm planning on stocking Malawi Haplochromis. Is that right? Thanks.

 

[jsoong]

You read it as soon as the color change, the depth of color doesn't matter much.

What is the pH? I suspect that it will be low as well. So if you are keeping Malawi's, you would want to buffer the water to higher KH & pH.

 

[fddlss]

The pH was at 8.2 or 8.4 the last time I tested it, which was about 5 days ago, by the time the cycle completed or was about to complete. Then, I didn't check the pH again until yesterday that it was 7.4 and KH 3 dKH, probably both dropped because of the cycle. I will perform a PWC today, I still don't have any fish, hope to have some by next week, one or two to start and increase the stock gradually. The pH right from the tap water is about 8.4 or 8.6 I don't remember exactly, and I never tested tap water for KH. I was told to leave a bowl with tap water for 24 hours and then check for pH and KH and that's what I will do, to get accurate readings and see if I need to buffer my water to have higher KH and therefore stable and more alkaline pH levels or if weekly water changes will do the trick without the need to buffer.

 

[fddlss]

I will give you the readings for my tap water, my tap water after being on a bowl for more than 24 hours, my aquarium water before a 60% PWC, my aquarium water after a 60% PWC, my aquarium water 12 hours after adding 1 PPM of ammonia.

OK, these are the levels on my tank and my tap water: I know some of the tests are unnecessary for tap water but I still tested for it.

Tap water right from the faucet:
Ammonia: 0.50 PPM
Nitrite: 0 PPM
Nitrate: 0 PPM
pH: 8.4
GH: 3 dKH
KH: 2.5-3 dKH


Tap water sitting on the counter for more than 24 hours:
Ammonia: 0.50 PPM
Nitrite: 0 PPM
Nitrate: 0 PPM
pH: 7.4
GH: 2 dKH
KH: 2.5 dKH


Water from tank BEFORE doing a 60% water change on Wednesday night:
Ammonia: 0 PPM
Nitrite: 0 PPM
Nitrate: 80-160 PPM
pH: 7.4
GH: Didn't have a GH test.
KH: 3 dKH
Temp: 87 F


Water from tank AFTER doing a 60% water change on Wednesday night:
Ammonia: 0.25 PPM
Nitrite: 0 PPM
Nitrate: 40 PPM
pH: 7.4
GH: 3 dKH
KH: 3 dKH
Temp: 85 F

Water from the tank on Thursday afternoon, 12 hours after adding 1 PPM ammonia in the morning:
Ammonia: 0 PPM
Nitrite: 0 PPM
Nitrate: 40 PPM
pH: 7.4
GH: 5 dKH
KH: 3 dKH
Temp: 86 F


I think I will need to buffer my water and increase pH in order to stock African cichlids, right?

Please let me know your opinions.

Thanks.

 

[jsoong]

Your water has very little buffers. The initial high pH out of the tap is due to "liming". The water co. add CaO or Ca(OH)2 to artificially raise the pH (to prevent corrosion), but the effect is short lived & the pH bottoms out after a while.

So yes, you should be buffering your water to a higher pH. Crushed coral is prob. the easiest & most fool proof. A commercial buffering salt mix is another option.

 

[fddlss]

I'm probably going to go by my LFS today and get a bag of crushed coral to place in the sump.

I will try to raise my GH to 16 dKH, KH to 12 dKH, and pH to 8.4.

By adding crushed coral ALL of them should raise, right? Not just pH?

My next question is, let's suppose I get some crushed coral from y LFS, I place it in the sump, and 24 hours later I'm lucky enough to get the pH, GH and KH that I want, wouldn't that change with every partial water change? At least the pH, being that my tap water has a pH of 8.4 right from the faucet but after a few hours it drops to 7.4. Would the crushed coral raise the new water's pH before it drops? Will KH do the job on keeping a stable pH even when there's a PWC? I really don't like the idea of leaving buckets everywhere overnight for PWC's.

Thanks.

 

[jsoong]

Yes, cc will raise all 3 of the parameters. pH of 8.4 is just about the equilibrium point for CaCO3, so you don't have to worry about how much cc to add. Just add lots & the cc will dissolve in until saturated, which should be just about where you want it. <Remember to add more cc as it gets used up.>

As for pwc ... there will be parameter shifts until the new water becomes saturated with cc. This generally takes 24-48 hrs. If you want to be perfect (or if you are doing a big pwc), you wound want to pre-dissolve the cc in the change water. It is a bother to have buckets of water hanging around, tho, so most people, doing small pwc (say up to 10%), will just use the tap as is. The small shift is not too bad. For an emergency large pwc, when you don't have any prepared water, then you can make a reasonable match by dissolving baking soda into the change water to match the KH & pH as close as possible.

 

[fddlss]

I agree, I think you just gave all the different options. Thanks. I added CC last night, about 8 pounds and there was no difference in pH this morning, it probably takes a day or two. On the other hand, I've always used the High Range pH from API to test for pH, but this morning I decided to try and see what the pH test said and it was 7.6, so the high range pH gives me 7.4 (lowest in the chart) and the pH gives me 7.6 (highest in the chart); However, I also have the Seachem pH alert in my sump and that reads 7.4. I guess I should just go for what the high range pH test says and forget about the lower pH test.

 

[fddlss]

KH and pH are the same after adding CC 60 hours ago, should I keep waiting or add more CC?

 

[jsoong]

Strange .... Where is your cc? Is there water circulation through the cc? I would try moving some cc to a water filter to make sure things dissolve faster.

 

[fddlss]

It's in the sump. Right below the submersible pump. It's been 4 days now, with no change. KH 3dKH, pH 7.4, GH 3 dKH, Temp. 86 F

 

[jsoong]

I am stumped .... some thoughts on what might be the cause:
1. The cc is not fine enough, or is coated, or is actually not CaCO3 ....
2. The water is saturated with some kind of buffer that is preventing cc from dissolving in ..... This is a theoretical possibility, but off hand I can't think of anything that will do that (and not be detected as KH).

One suggestion: take some tank water & dissolve in some baking soda, see if you can increase the KH & pH. If you can, that rules out #2. (And also rules out errors in testing.)

 

[fddlss]

The CC is from CaribSea, Florida Crushed Coral and it says in the bag that it's one of the best buffers available. However, I got it from my LFS and the bag looked pretty old, I don't know if that might have something to do or not.

On the other hand, I've tested my water and these are the parameters:

GH 7 dKH (raised a little since last time I tested)
KH 3.5 dKH (raised 0.5 -close to nothing, since last time I tested)
pH 7.4 (same as last time I tested)

Then, I took a cup of aquarium water and added a full teaspoon of baking soda. This was probably a huge amount of baking soda for a cup of aquarium water. These were the results:

GH 3 dKH

KH 20+ dKH (I stopped counting after 20 dKH, it was electric blue and it's supposed to be yellow, so I figured that it would take dozens of drops to change it to yellow)

pH 8.2 (It wasn't the exact same color as the color of the 8.2 measurement on the API test kit chart, but it was similar to it.)

I'm adding about 1.25 PPM of ammonia every morning to feed the bacteria while I don't get the fish. Could these be the reason why crushed coral is taking so long to buffer? It takes about 10 hours to drop Ammonia and Nitrites to 0 PPM after I add 1 to 1.50 PPM every 24 hours. My nitrates are probably high, maybe that's another cause?

Thanks for your help!

 

[jsoong]

ammonia & nitrates are not enough to mess with a bicarb buffer. Since you can raise the pH & KH with baking soda, that would proof that the water is capable of dissolving in the carbonates. Just have to figure out why it is not doing it with your cc.

Solubility of CaCO3 is CO2 dependent. That might be a problem if the water is stagnant. But with a sump & pumps, this should not be a problem. Perhaps the cc is in a locally stagnant area. Moving it to a different area or spreading the cc out might be worth trying.

Another possibility is that the cc is too coarse, or its surface coated with something impermeable. As an experiment, you might try pounding some cc into a powder with a hammer & seeing if that will dissolve into a cup of tank water.

 

[fddlss]

The cc is in the sump, right next to the sponge and it is in the compartment where the submersible pump stands. Basically is like the substrate of the sump but only in the part where the pump is. Then, I have the sponge that divides the 2 compartments and then the bio-balls are in the other compartment. There's an empty space right below the bio-balls, maybe I should try adding some more cc there? or move this one there? there's also a small (0.75 inch) air stone in between the pump and the sponge. I will try the hammer experiment.

 

[jsoong]

If it is under the pump, that is a dead spot. If I have your setup correctly in my head ... water will overflow the baffle into the pump compartment & be picked up by the pump inlet. There will be little water movement below the pump.

Try putting the cc in the wet/dry compartment with the bioballs, you might have better luck.

 

[fddlss]

If it is under the pump, that is a dead spot. If I have your setup correctly in my head ... water will overflow the baffle into the pump compartment & be picked up by the pump inlet. There will be little water movement below the pump.

Try putting the cc in the wet/dry compartment with the bioballs, you might have better luck.

You are right! I made an illustration of my sump so that you can have a better idea. I should move (or add more) the CC to the area that's labeled "empty space" on the illustration, right? since water will HAVE to flow through the CC.

 

[fddlss]

24 hours after moving the CC my pH has raised to about 8.0, KH to 4.5 dKH, and GH to 8 dKH, one degree for KH and KG, and pH went from 7.4 to 7.8 - 8.0. Let's see if it stays stable! If it stays stable, then it will be a matter of doing some small PWC to drop nitrates and finally get the fish!

 

[jsoong]

I am glad we figured out the mystery of the cc not dissolving. Give it a few days for everything to stabilize. The pH should go up a few tenths more to reach equilibrium.

 

[fddlss]

Sounds good. I'm still waiting and KH, GH, pH has not moved any further, it's been 3.5 days now. You are probably going to say I'm dumb, but I'm really getting very inpatient and would like to start stocking my tank, at least with 3 or 4 fish this week. Can I do a PWC to drop nitrates and stock the tank with the first 3 or 4 fish? Even though my water is not really hard for Africans, could I still bring home some fish and keep waiting to see if CC does something and if it doesn't should I gradually add baking soda a little bit every day or every other day until the water is hard enough? I know that if I waited this long I should just wait a little more, but like I said, I'm really tired of seeing that empty tank and I would like to know if my fish will survive under those conditions. Thanks.