So Frustrated---why Won't My Aquarium Cycle?

  • #1
New to this forum. I purchased a 29-gallon aquarium the first week of July---an Aqueon kit with an LED hood, 100-watt heater, and Quiet Flow 20 power filter. I set it up in my classroom, added 25 lb. Cumberland River Gems pebble substrate, with a small "beach" on one end of the aquarium, both for aesthetics and because I had read that cichlids like to dig around in sand. The sand I added was 5 lbs. of Ocean Direct Caribbean Live Sand. I also added various artificial plants, décor, etc., making sure that I had 4-5 cavelike areas for cichlids, some polished rocks from the fish store and a few colorful quartz rocks that I had collected on a trip. I also added about 3-4 very small seashells to my "beach area." I filled it with tap water (used water conditioner) and let it run for several days (didn't know enough at the time about nitrogen cycle to know I should have added a little food along to speed the process...)

A coworker had a tank with one lonely cichlid left in it that I adopted, and 4-5 days later I put him in the tank (which I had treated with API Quick Start), followed a few days later by 2 Glo red barbs, 1 eclipse catfish, and 3 small African cichlids. Yep, didn't know I should have waited longer to add fish, and then should have only added 1-2 at a time, but patience is not my strong suit. A week later I added 6 more fish---4 small tiger barbs and 2 more small cichlids.

In spite of all my newbie mistakes, all was going well with the fish until early August, when fish started dying---sadly the barbs were the first to go. I was doing partial water changes with spring water rather than tap water, reading all I could trying to find answers, but my testing was limited to test strips, which I now know are not very accurate, and which did not include an ammonia test. A former student advised me that it sounded like an ammonia and sent me a bottle of Prime to treat with, but still fish were dying. Within a week, I had lost all of my barbs, and the 3 smallest cichlids soon followed.

Maybe I'm nuts, but it seems like my troubles began when I changed the filter cartridge about that same time. I also added a Quiet Flow carbon cartridge with bio-media filter grid. The info that came with my aquarium had said to change the filter cartridge once a month or when it began to look dark brown, so that's what I did, and within 2 days fish were dying. Would this have caused my ammonia levels to spike? At about the same time that things went south, I noticed an odor to my water that I had never noticed---will high ammonia levels cause that as well?

I quickly ordered an API test kit when fish started dying, and sure enough, ammonia levels were high (looked to be about 4.0 ppm). Since then I have done 6-gallon partial water changes once or twice a week, using spring water, and the remaining 4 fish (3 blue cichlids and the 1 catfish) seem fine, but I see no sign that my tank is cycling. Ammonia levels are consistently 1-2, nitrates and nitrites I check only occasionally and they are always nonexistent. Today I checked ammonia because it had been about a week since I did a water change, and levels appeared to be somewhere in the 3.0 ppm range. I quickly did a water change of 8 gallons, with spring water that tests 6.2 pH and shows no ammonia. Forgot to mention that pH is also running high---as best I can tell it is running in the 8.0-8.2 range? Surely my 4-5 small seashells are not the culprit? I added a 4-inch cholla log several weeks ago to try and help lower the pH naturally.

I apologize for the length of my first post, but I would love to know if anyone has any advice on how to get this tank to cycle, and what I might be doing wrong? I don't think I'm overfeeding. I give them a small pinch of cichlid pellets each day and a tiny pinch of flakes for the catfish. And goodness knows after all this trouble I will be scared to change the filter cartridge forevermore!

Levels today prior to 8-gallon partial water change:
Ammonia 3.0-4.0 (Don't really feel confident with my test kit color-comparison abilities yet!)
pH 8.2
Nitrate 0
Nitrite 0

Thanks in advance for any guidance you can offer!
  • #2
By spring water, do you mean bottled water? Do you know how hard or soft the water is? If very soft, it can lead to parameters bouncing around.
  • Thread Starter
  • #3
I'm buying gallon containers of natural spring water, which test at 6.2 pH and zero ammonia
  • #4
I had the same issue. Aqueon starter kit, didn't know the full extent of the Nitrogen cycle and had a lot of problems early on. I would say you added a LOT of fish early on, before the tank was ready, as did I. Also, the filter change phenomenon also happened to me. The problem with the Aqueon Quiet Flows is that they have literally nowhere for beneficial bacteria to grow and thrive, other than the carbon filter. They have the lame surface area rods and tiny sponge, but I don't think that's enough whatsoever. Also, a single 20G filter on a 29G tank is on the low end of filtration.

My fish were fine and Ammonia levels had dropped, then I took the filter out to clean it and it crashed. I just don't think you can rely on that filter to house enough bacteria. I added a second 10G filter that had compartments for bacteria media. Certainly the 10G is not enough alone, but in conjunction with the 20G filter it works. I added ceramic rings and sponges to the compartments of the filter. I'm still going through the cycling, but have lost no more fish and the fish I have are more relaxed and exhibiting more healthy behavior.

You probably need to use bacteria supplements, like Seachem Stability or TSS. They both have bacteria that adding to the tank will help start colonies of good bacteria that drive the nitrogen process and convert Ammonia to Nitrite and then to Nitrate. I would start with getting a secondary filter with more bacteria-friendly media, add some bacteria through Stability or TSS, and just continue with the water changes. Don't feed the fish as often in the beginning so that they are producing less ammonia. You can dose the bacteria supplement daily until the cycle completes.

I hope this helps. Good luck.
  • #5
HI there. Welcome to Fishlore!

So your tank isn't cycled for a couple of reasons. API QuickStart needs to be used with an ammonia source. So if you used it without fish in the tank, then the bacteria died off before they could establish your cycle.

Secondly your filter media (cartridge) is where your nitrogen cycle lives. By throwing away the cartridge, you threw away any bacteria that was there. Instead of throwing away the cartridge, rinse it gently in dechlorinated water.

You need to stop using spring water. Adding water that has a 6.2 pH into a tank with a pH of 8.0 will cause your fish to go into osmotic shock. It will kill them. It is better to have a stable pH, than a perfect one. Your fish will adapt to an 8.0 pH. So don't mess with it at all. Remove the seashells. Yes they will raise your pH. Even just the couple you have in the tank. Your pH should stabilize after removing the seashells and doing the water changes.

Now onto your Ammonia. You need to do 2 back to back 75% water changes ASAP. (About 20 gallons x 2) This should get you down to 0.25ppm of ammonia. This is the only safe level of ammonia, unless you are using Seachem Prime as a dechlorinator.

Onto Supplies. You need to get some Seachem Prime, & bottled bacteria (I prefer Seachem Stability, but API QuickStart will work too). If you don't have a Python water changer, I recommend it highly. Saves your back some work.

Seachem Prime will replace every other water conditioner. It is a dechlorinator, stress coat, and it detoxifies ammonia, nitrites, and nitrates up to 1ppm for 24-48 hours. This is essential to protect your fish during a fish in cycle.

I am going to add some tutorial videos I like to share with new fishkeepers. It is great info on filter media and optimizing your filter. Along with why larger water changes are necessary to change water chemistries.

Edit: You also do need to upgrade your filter. As a side note. The Aqueon 20 only has a gallons per hour(gph) of 125. For a 29 gallon tank you will need a filter with 8-10x's the tank volume. So right around 300gph. By upgrading your filter, it will help keep your Ammonia down. I also suggest adding a couple of sponge filters to your tank for added filtration and surface area to grow bacteria on.

I recommend a Seachem Tidal 75 powerfilter. It is a great hang on back, and is very quiet. But there are others that work just as well. I would avoid any bio-wheel filters as they tend to be troublesome.
  • #6
Do you have anybody in your area to give you some used filter media? That will instantly cycle your tank.
Is Ocean direct live sand an appropriate substrate for fresh water tank?
How hard is the "spring water" you are using? It should be on the label, expressed in ppm.
I would do daily water changes (40-50%), conditioned with Prime, no feedings for one week.
  • #7
Agreed on all above. You may not need to add another filter, but I still think the Quiet Flows offer very little surface area for bacteria to establish. And yes, Prime is your best friend when used correctly.
  • #8
Agree with above 6.2 PH is a problem if your trying to get a tank to cycle. Bacteria has a hard time reproducing in a PH below 7.0.
  • #9
After re-reading your post I see that you are already using Prime. Follow this formula, and it should get you cycled. If you choose to use API QuickStart or Seachem Stability for bottled bacteria, just add it into the formula. If you use a different bottled bacteria like Tetra Safe Start plus, this formula doesn't work for it.

Ammonia + Nitrites = less than 1ppm, add full tank volume of Prime and bottled bacteria. Recheck parameters in 24 hours.
Ammonia + Nitrites = 1ppm or greater, do 50% water change. Add full tank volume of Prime and bottled bacteria. Recheck parameters in 24 hours.

Prime dose is 1ml per 10 gallons. Your dose is 3ml for your 29 gallon tank. It needs to be added everyday, until you are cycled. to protect your fish.

The goal with water changes is to lower your Ammonia and nitrites to below 0.5ppm, so you may need to do greater than a 50% water change to achieve that.

If you have any other questions, please continue to ask. We can get you cycled. You just need to tweak a couple of things and you will be successful.
  • Thread Starter
  • #10
Thanks so much to all of you. Will watch the videos you kindly posted tomorrow, and do more water changes this weekend! Will remove my few little seashells. I have been using QuickStart with every water change, actually used the last of it today, so will order the Stability to take the place of it, and will use Prime this weekend as well. Will skip the feedings over the holiday weekend (I'll have to stand strong and look away from the fish and their hopeful faces when they see me!) Looking forward to the day I see signs of cycling!

By spring water, do you mean bottled water? Do you know how hard or soft the water is? If very soft, it can lead to parameters bouncing around.
Will try to check label at school tomorrow and see if shows levels.
  • #11
As noted, the bacteria struggles in more acidic water. I added some crushed coral to improve the hardness and pH of the water. Now I sit around 7.2-7.6. As soon as I improved the pH, the fish became more active, especially the shrimp.
  • Thread Starter
  • #12
So when I do these additional water changes tomorrow and again over the weekend, I will use tap water instead of the bottled spring water. Am also going to look into replacing the filter---will just need to find one that works with the openings in my tank's hood. At least my four remaining fish are hanging tough through my bumbling efforts thus far. They act ridiculously healthy and happy under the circumstances, and my students love having an aquarium in the classroom. Hopefully with all y'all's great advice I can conquer the cycling problem and eventually add a few more fish---1 at a time.
  • #13
You don't need to replace the filter, but you can supplement with a filter that has more surface area for growing bacteria. I didn't replace my quietflow 20, I just added a 10 gallon filter with compartments off Amazon. It has a spray bar, too, which has worked wonders for my water surface. I'll look it up and post here.

Penn Plax Cascade 300 Submersible Aquarium Filter Cleans Up to 10 Gallon Fish Tank With Physical, Chemical, and Biological Filtration

This is what I added. I didn't use the carbon filter since the quiet flow has that already. Instead I put sponges and ceramic rings to home bacteria.

The spray bar is great. Mine is very quiet. It suctioned to the back of the tank.
  • #14
So when I do these additional water changes tomorrow and again over the weekend, I will use tap water instead of the bottled spring water. Am also going to look into replacing the filter---will just need to find one that works with the openings in my tank's hood. At least my four remaining fish are hanging tough through my bumbling efforts thus far. They act ridiculously healthy and happy under the circumstances, and my students love having an aquarium in the classroom. Hopefully with all y'all's great advice I can conquer the cycling problem and eventually add a few more fish---1 at a time.

Yes definitely use the tap water. Be sure to use Prime with the water changes. I suggest doing a full set of water parameters on your tap. Just so you know what you are starting with. It will help in the long run.

Most hang on back filters fit within the confines of the lid. But definitely not all. You could add a second filter, as was suggested above. Instead of just replacing the one you have. I would also add sponge filters. They are super cheap, all you need is a sponge filter, airline tubing, and an airpump. They work similar to an airstone, but they provide additional biologic filtration. It could work for you in the short term. It can up your gallons per hour as much as 100gph. Plus it will help get your tank cycled with the added surface area. I have sponges in all my tanks. I highly recommend them. They are also wonderful for doing instant cycles on an emergency hospital tanks. You can pull the sponge filter out, add it to an emergency set up and your tank will be cycled. That easy.

Another thing to consider is setting up a small 10 gallon quarantine tank. It is a place to keep your fish for 3-4 weeks before adding to the big tank. Sometimes the fish you get from the pet store can be sick. If you add them to the big tank, it can make your healthy fish sick. So a qt is the safe way to add fish to the big tank. That way you can observe or even treat an illness before infecting your entire tank. That way you can get a group of 4-6 fish, quarantine them for 3-4 weeks. Then add them to the big tank all at once. After I was done stocking my 29 gallon, I used the 10 gallon to house a betta. So it was a win win for me lol

Here is my 29 gallon set up today. You can see I have the Tidal 110 filter (it is bigger than you need, but it was on sale) plus 2 sponge filters. I have a glass lid, and a beamswork led light with a timer switch. I set the tank up initially in April, and have slowly upgraded everything as I have went along. I just discovered 2 baby catfish last week. So I must be doing something right.

  • #15
Poor you, I got stressed just reading your post. I always do fishless cycle as I can't bear watching fish suffer.
You can speed it up A LOT if you can get filter media from an established tank. Maybe your LFS will give you some?. I've also had luck with tetra safe start. Fast growing stem plants will help. I've not found it to be an instant cycle but I can be cycled in a week to two weeks (dosing with ammonia) rather than the six weeks it took my first tank to cycle (no established media).
  • #16
My sons science teacher wanted a class tank, but didn't know much about them. Luckily my son spoke up and let her know he could help. I sent him in with seeded media (to give the tank an instant cycle) then he took charge of tank maintenance. The fish took there summer vacation in my tank. Mabee 1 of your students have a tank at home and can give you some seeded media? That could save you lots of trouble.
  • #17
Oi. I feel your struggle. Sorry about your predicament.

Imo the formulas for cycling aren't necessary if you're willing to fully commit to large daily WC. I had 2 very sick goldfish and no cycle recently and thought to try to spare them the struggle, but in the end decided to do it like I always do: fish in, a ton of biomedia in, 30% water changes with prime daily for about a month. Done.
I also used seachem stability to be gentler with the fish; not sure if it helped, but it definitely did no harm.

You're right, the cartridge probably housed your bacteria. That would definitely crash your cycle. Stuff the quiet flow with media this time around, and cartridge change should be like every 6 months at most. It's a sales gimmick.

How many fish do you have left? If it's a couple of cichlids in a 29 without any real plants, all you need is a bottle of Prime and daily commitment. You don't even need spring water.

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