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KH and Nitrifying Bacteria

3K views 36 replies 10 participants last post by  JessiesGill 
#1 · (Edited)
Cycle going nowhere - I'm stumped

There isn't really a good place to put this question, so here seems the best place.

I understand the nitrogen cycle pretty well, but I've run into something that has me stumped.

First the question: Is there a direct relationship between KH and the growth of Nitrifying Bacteria?

Here's why I ask: I am cycling a tank at the moment with ammonia. I have a starting point of 5ppm ammonia concentration in the water.

The starting water parameters are PH 7.9, KH 1dK and temp 78-80 degrees.

I have seeded the tank with Bacteria, a couple of different products actually (Seachem Stability for 7 days, then Nutrafin Safe Start Plus on day 8). After 9 days, I am seeing no movement whatsoever either in ammonia or nitrite levels. I've used tests by API and Nutrafin each time I measure to be sure I am getting accurate measurements. The tank I cycled previously showed nitrites on day 3 after seeding the tank, and I am stumped as to why nothing is happening in this tank.

Someone suggested to me that my low kH levels are inhibit nitrifying bacteria growth and function. I know that as PH values lessen, nitrifying bacteria growth and function slow and eventually stop altogether at around PH 6, and that there is a direct relationship between PH and KH. As my starting kH is so low, this comment piqued my interest.

The only problem is I can find nothing on the internet that corroborates a relationship between kh and these bacteria. Only about PH. Now I know that nitrifying bacteria use (among other things) carbon in the water to do their thing, so does that mean if the carbon source in the water is either very limited or non existent, they stop working or fail to grow at all?

Of course I may be missing the boat entirely, in which case, I'd love to know what is going on. There you have it. Your comments and experience are welcome.
 
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#2 ·
Boy, I ask the damnedest questions, don't I?... lol. I really gotta stop that :)

What I really want to know is if anybody has any ideas about why my cycle isn't going anywhere. Ph and Temp are good, ammonia in the water, bacteria seeded.... Nothings happening after 9 days.
 
#3 ·
Would love to see if anyone has an answer to your question. I've been unable to cycle a tank after over 2 months. And I use store-bought drinking water and am starting to wonder if it's the water's "lack of hardness" or being "too pure" that's keeping the cycle from progressing.
 
#8 ·
If you have been really stuck, I would suggest trying Dr Tim's One and Only. I was stuck for three weeks and ordered a bottle. My ammonia was going down due to evaporation or plant consumption. The next day I had nitrites. After 3 weeks of Dr Tim's, my cycle is almost done. ;D I wish I ordered it from the start. It definitely gave me the boost that I needed and it isn't the type of bacteria in a bottle that you have to keep adding back into the tank (redosing). Maybe I should start a thread on Dr. Tims. It's wonderful stuff, especially when you have no access to seeded media or when nothing seems to be happening.
 
#4 ·
I'm following this thread, too. I had a 2.5 gal that didn't cycle in 6 weeks after getting a sponge filter. I test for ammonia, nitrites, and nitrates, but I haven't tested for pH, hardness, etc. I figured I didn't need to test for them, since most folks here recommend not messing with those anyway. But I am curious to know if there is something that makes my water more difficult to cycle.

Where are those chemistry experts? :)
 
#5 ·
Did you test for nitrAtes? With all the jump start stuff you've added, if the tank went and cycled itself already, you'd only see nitrAtes. If ammonia is still showing, maybe it's too much for the BB to handle, as it's settling into a newly started cycle.
I don't know about KH affecting a cycle, so can't help you there. I just figgured I'd see if you were testing for the nitrates, since you didn't mention those, just nitrites.
 
#7 ·
That's a fair question, and yes, I have measured Nitrates daily. Always 0. I wouldn't expect to see any just yet as the ammonia concentration in the water remains constant.

Your ammonia starting point is too high. Aim for 3ppm. That's what's inhibiting the cycle.
A guy at my LFS also suggested the ammonia levels are too high, that it may have shocked the nitrifying bacteria; however, I am having an extended conversation with someone on a different forum about this topic. He's clearly very knowledgeable about it, and he told me the ammonia levels are not the issue.

In no way do I mean that as an insult givemethatfish. I am sure that you are also experienced in this area. I'm not ruling the ammonia level out just yet, but I want to see where this conversation goes.

Also, I restarted the cycle that is starting with these parameters. KH 3dk, PH 7.4 (came down after adding the sodium bi-carbonate to the water), Temp same. Have not yet added ammonia due to the extended conversations and ideas I am reading and talking about.

I appreciate all of the input and I am seriously considering each piece of information that comes in. I feel like I am gradually zooming in on the answer here. I'll post what I find.
 
#12 ·
Here's what I have learned and what I am going to do.

Does KH affect the initial growth and function of the nitrifying? Well, yes and no.

The carbonates in the water are only one thing of many that have an impact on these bacteria. Other elements like light, nutrients, trace minerals, oxygen, carbon dioxide, salinity and alkalinity all play a part. So to point at any one thing and say "AHA!!! That's It!" just isn't possible for us lowly hobbyists with limited means. I believe it would take a biology lab and micro-biology degree of one sort of another to be able to really see what is going amongst all these elements.

The only thing we can see that is measurable is the PH and its affect on these bacteria. The more acidic the water as measured by PH, the more inhibited the bacteria are until they stop functioning altogether (PH 6.0). But in an established aquarium with plants, fish and other bacterial growth and function throughout the rest of the aquaria and substrate, this gets a little more involved as there is give and take from each element in the system. Don't ask me what they are just yet. Give me some time and I'll find out about it.

So what does that mean? Well, I am taking the bits and pieces I have received and doing the following (I started over by emptying the tank, making the adjustments needed).

1. Raise the KH to minimum of 3 dk. mine is at around 4 dk.
2. I am seeding the aquarium as directed using Microbe-Lift Nite-Out II (Sorry folks. Someone beat you to the suggestion :)).
3. Adding ammonia to the system slowly over several days until I reach 3-4 ppm concentration.
4. When Nitrites show up, letting it drop to .5ppm and holding there till the cycle completes.
5. Adding two bunches of Anacharis to the tank. Adding a biological element to the tank that for the cycle rather than letting it remain sterile.
6. Adding aeration.

Now if it goes quicker this time, I won't be able to point to any one thing to say it fixed it, but at least I'll know that doing it this way works.
 
#13 ·
took my tank just over a month to cycle (fish-in) i will say that Nitromax by Tropical Science did speed up my cycle significantly and maintains it very well. Ive been cycled for just over 2 months with no spikes in ammonia or nitrates both @ 0ppm and holding. maybe that will help your issue.
 
#14 ·
NanaBeams - thanks for your suggestion. I've seen Dr. Tim's mentioned around here several times, and that's my next choice if I try to buy another bacteria in a bottle (haven't had luck with the others). I may be able to get some seeded filter media from a very kind person ;-) but I'm very interested in this water issue because I want to make sure my water is good for sustaining the BB I introduce into the tank and it doesn't die off.

rdpadgett37 - thanks for sharing what you found out. Hope it works and please do post again and let us know how it turns out.
 
#16 ·
PH 6.4 (A couple months ago I tested it and got 7.2 so not sure why it's lower now) I've been using Stability trying to cycle it. Does this lower pH?

GH and KH - When I did the test I only added one drop of solution and got a pale version of the final color. I added a couple more drops just to verify, but it started out with the color it was supposed to change to with only 1 drop. I have the liquid API tests and the lowest reading for 1 drop is 17.9 but maybe you used a test that is more sensitive?

temperature 78 degrees.
 
#17 ·
Ok... First thing is it takes alot of mismanagement to kill off bb. As long as you don't boil them, freeze them or let their media dry out, you'll be fine. As I understand it, when the conditions are less than favorable, nitrifying bacteria growth rate and efficiency of processing goes down. Excess bacteria go dormant until conditions are favorable again.

For your water, the temp is good. Anywhere between 77-86 degrees is ideal.

Your PH is low for the nitrifying bacteria. Their growth rate and efficiency is very low at that level. At 6 (for a reference), they go completely dormant. I would suggest raising it to at least 7.2 or higher. The efficiency doesn't get ideal until 8.3. They'll do much better at 7.2 than at 6.4. The nitrifying bacteria will function at 6.4, but very very slowly.

We are really talking about raising your KH which is very low like mine. Baking Soda is the cheapest way to do it. I don't have a dosage chart I can link you too :-(, but instructions are readily available as to how much to add. I use something different but it accomplishes the same thing and my KH is now at around 50ppm (about 2.8-3 dK) which gives me a PH of 7.2.

Your GH is really low, too, just like mine. It is a shot in the dark, but it makes sense that if these bacteria use trace minerals, then a higher GH would be beneficial. Most of what comprises GH tests is calcium and magnesium, but there are a number of trace elements that don't get measured in the test as the amounts are so tiny. The easiest way to raise it is with crushed coral, either on the bottom of the tank or in your filter. Filter coral will leech the minerals into the water faster but both will work. You can get it at your local gardening center. I raised mine to 70ppm (about 3-4dH).

I've read in more than one place that aeration during cycling is good for the growing bacteria. A small pump and airstone will do the trick.

Hope that helps. Best I can do right now :)
 
#18 ·
It's my understanding that most "drinking" water these days is produced by reverse osmosis (It's now cheaper than distilling) with added minerals for flavor. And who knows what those are?

If you're fishless cycling with ammonia for a Betta tank, any dosing over 1.0ppm is just a waste of ammonia and an overgrowth of bacteria which will die back soon after stocking.

Stability doesn't contain the cycling bacteria you want to cultivate. Your (Tetra?) Safestart may have bee frozen in shipping. I expect a lot of that after this winter. Dr Tim's is shipped factory direct in an insulated envelope, which helps.

I compliment you, rpadgett, for learning all you can about water parameters and what determines the various aspects. But try not to over-think it. Sometimes patience is all that should be practiced.
 
#19 ·
If you're fishless cycling with ammonia for a Betta tank, any dosing over 1.0ppm is just a waste of ammonia and an overgrowth of bacteria which will die back soon after stocking.
I have been suspecting recently the instructions I have lived by for an ammonia cycle may be flawed. First time anyone has said this. I was under the impression the bacteria just went dormant, but if the excess dies off, then the instructions I have used are going out the window. Appreciate the info here.

I compliment you, rpadgett, for learning all you can about water parameters and what determines the various aspects. But try not to over-think it. Sometimes patience is all that should be practiced.
Fair enough, Hard to not over-think at times due to conflicting information, but I definitely agree, patience is a virtue here. I've been told that is true everywhere. I've been thinking really hard about that one... hehe :)
 
#20 ·
Re-Reading. Yes, your knowledge base is pretty solid. You finally mentioned temperature and aeration as considerations. I think all you missed is current flow, which spreads the bacteria and exposes more water to the bacteria for treatment.

The realtionship between bacteria and plants is simple. The more plants the less bacteria -- plants eat first. The fewer plants the more bacteria is necessary to pick up the slack.
 
#21 ·
Yes of course, water flow makes perfect sense. I had begun to wonder about that when thinking about my filter.

I use an aquaclear 20. With water flow through the filter, is it better to use the bags with ceramic balls that came with the filter or a fibrous bio media pad? The water flows past the stock bio-media pretty fast. Fiber pads have more surface area and volume in contact with the water so I wonder if they are a better choice.

Is it?
 
#22 ·
I like AQ sponge. Filter floss is good. Both hold more bacteria than ceramic balls, but they each need regular rinsing -- more for the floss.

I'm sure there's an optimum dwell/exposure time for the water flowing through the bacteria. I'm sure it varies with the media (filter foam, substrate, decor and plants surface area.) I'm sure I don't know what that is in absolute terms. In the process of the tank becoming "established" the bacteria naturally grow to a balance among the various media.
 
#23 ·
Even if I did know that, I doubt there would be a way to control that flow to get the exposure time. That's beyond even what I want to know, and I do believe that as the tank gets established it balances out throughout the entire eco-system which is good enough for me :)
 
#26 ·
For anyone still following this thread, I found the answer after doing some very exhaustive research.

There IS a direct relationship between nitrifying bacteria, particularly with Nitrosonomus (breaks ammonia down into nitrite), and the KH of the water. Pretty simple how it works.

This bacteria burns ammonia and O2 for energy to break down carbon in the water (carbonates / bicarbonates and CO2) so that it can grow, producing nitrite as the byproduct. It is particularly fond of carbonates / bicarbonates. The higher the amount, the faster the growth of this bacteria will be.

So what does that mean? The lower the KH, the slower will be the growth of the nitrifying bacteria.
 
#27 ·
Do you have a recommendation for me? Is there a way I can increase KH easily and safely? I moved my betta to a 10 gallon, since I was unable to cycle his 2.5 gallon after 4 months. He's been in the new tank for 2 weeks. I added TSS and saw an initial decrease in ammonia, but it was very brief. I've never seen nitrites. Something is preventing the bacteria from colonizing.

I don't have test kits for pH, kH. I just have the big 3: ammonia, nitrite, nitrate. I did have a very old pool test strip, and it looked like pH was 6.8. However, I realize that it could be way off. Do you think I should get another test kit? Is there a measure I can take now that won't harm my betta? I have a bottle of Dr. Tim's arriving tomorrow, and I want to do anything I can to increase its chance of success.
 
#28 · (Edited)
Do you have a recommendation for me? Is there a way I can increase KH easily and safely? I moved my betta to a 10 gallon, since I was unable to cycle his 2.5 gallon after 4 months. He's been in the new tank for 2 weeks. I added TSS and saw an initial decrease in ammonia, but it was very brief. I've never seen nitrites. Something is preventing the bacteria from colonizing.
Hi JessieGill. First things first. You are doing the right things, so there's no need to worry.

I don't have test kits for pH, kH. I just have the big 3: ammonia, nitrite, nitrate. I did have a very old pool test strip, and it looked like pH was 6.8. However, I realize that it could be way off. Do you think I should get another test kit? Is there a measure I can take now that won't harm my betta? I have a bottle of Dr. Tim's arriving tomorrow, and I want to do anything I can to increase its chance of success.
I would recommend getting a PH test kit, but hold off on a KH test for now. There are several things that could be contributing so lets look at that first. And you are already doing your testing for ammonia, nitrite and nitrate now, so don't worry about testing for anything else except your PH.

These first questions are probably silly, but I need to know more about your situation and what you are doing.

Are you cycling the tank with your betta in it? Sounds like you are but just want to be sure.

Are you doing your water changes when the ammonia concentration reaches .25ppm?

What filter do you have running in the tank? Does it have ceramic beads or pads for the bio filtration media?

Do you have a heater?

Thanks for your indulgence here :)
 
#31 · (Edited)
I read through the entire thread you gave me and you have been a very busy girl :)

There are four basic things the BB need to grow, plenty of open surfaces, Oxygen (the more the better), good water flow (BB get their nutrients the most from the flowing water which is why they will settle into the filtration system first), and Ammonia. A carbon source is important, but we can revisit that at a later time if need be (most water has plenty of carbonates and CO2 in it).

Things that help provide a good environment for the BB to grow and function well are PH (7.8 - 8.3 ideally), Temp (77-86 is ideal), and low lighting. Now for the questions.

Your filter. Is the connection between where the sponge meets the tube water tight? Same for the bottom attachment. Does any water flow through any seems between it and the sponge? You want to avoid any water bypassing the sponge. If there are any leaks and water is not coming through the sponge consistently, you'll only get small areas of BB growth on the sponge (where the water flow is greatest). Remember the BB like surfaces with the most contact with flowing water. Your sponge needs to be airtight / watertight with all water coming through it.

I'm not saying you need to go get one of these but this is what I use. water flow through it is very good. These are made with double sponges as well:

http://www.amazon.com/Como-XY-2830-...4&sr=1-12&keywords=sponge+filter+for+aquarium

Second, the second sponge you have in place is a mechanical sponge. That one isn't made as a bio media so it isn't really doing you any good. Plus, like above, any sponge you add will also need the water to come through it, not around it, otherwise BB won't colonize it very much if at all.

Your temp is great, but if your PH is at 6.8, that will slow things down a little, but it isn't a deal breaker. I see no reason to change it. You will need to continue to be patient as the process will begin eventually. All things being equal, it just takes a little longer at that PH.

I would definitely add an airstone to the tank as soon as you can. I would also turn up the air flow from the pump to as high as your betta can tolerate. That helps to oxygenate the water which BB love. Plus, they are competing with another type of bacteria in your tank for that O2, so you want to pump as much O2 into the water as you can.

Lighting can be an issue. BB grow best in low light (I often wondered why the filter cases are made from the smokey glass. Now I know). I am not sure how to adjust that with your sponge filter being in the tank. Shade it as best you can. Also if your lighting puts off any UV rays, you will want to leave it off during the first few days after you add Dr. Tim's.

That's it for now. Keep us posted. I am keenly interested in how this turns out :)
 
#34 ·
I think your lighting is ok. Maybe just cut back on the lighting for a couple of days.

And the more I think about it, the more I think your sponge filter may be the culprit in this story. I am certain the stock filter was inadequate simply because the only part of the filter getting any water flow was at end, not over the entire pad. With the sponge filter, with it being so shallow top to bottom and very thick, I am not convinced you are getting good water flow throughout the sponge.

If you are planning to get another sponge, you'd be better off getting the one I showed you with the two sponges. They are just over 6 bucks and if you don't mind waiting a few days, I believe you will be better off. I don't think you will be loosing anything in terms of BB. If there are any in the sponge, their numbers are so small as to be insignificant.

This sponge filter has a larger foot print in your tank if you don't mind that, but not much, and the water flow through the sponge is very good. If you do get one, wait till it comes in before adding Dr. Tim's.

To find it, go to Amazon, pet supplies and search for sponge filter. Should be the first one to come up.

And no worries. I am happy to help no matter what thread it is in :)
 
#35 ·
Ive noticed on a few other sites that they recommend waiting 24 hours after using a water conditioner before adding your bacteria. And not to do ANY water changes for 14 days if using something like Tetra Safe Start. The conditioner apparently messes with the bacteria from those bottles.
 
#36 ·
That's what Tetra advises. Seachem says Prime-treated ammonia can be used by the bacteria. Most of the other ammonia-locking conditioners (Stresscoat, AmmoLock, etc.) are the same.

If you wait 24-hours, the ammo-locking chemical releases the ammonia it back into the tank to be used by plants and bacteria. In the meantime your fish are exposed to it.
 
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