I cant cycle my 5 gallon tank!

[AlbanyFishGuy]

Hi there,

Gonna try to keep this brief as i can but sorry in advance for long story....

I have a 20 gal, a 10gal and a 5 gal. The 20 is about 4 years and established. The 10 gal used to be a hospital tank but was converted to be a fry tank after my honey guaramis bred for the first time. It is now home to 6 juvenile but near adult guaramis. Was cycled with seeded sponge filter from the 20gal. Both tanks have tons of plants and the 10g has a DIY filter that i made out of a breeder box just for fun. (On top of the sponge filter) Both tanks have been running fantastic. But this left nowhere for fry. Guarami fry are RIDICULOUSLY TINY! lol We use a plastic shoebox for the first 3 weeks, then transfer them into a breeder net in the 10 gallon. But they dont survive as well for too long in the net we have found that they do best if theyre freed into the full tank and skip the net. Buuut...the juveniles will eat them. So what does a obsessed fish person do? Accepts this as a reason to buy a new tank of course! Hence the 5 gallon. I set it up, cycled it. I fed a little food and used stability until tests read no ammonia, no nitrite and 10ppm. When i finally achieved this....a fish became sick and needed to be quarantined. We didnt have fry yet so i used the 5 gallon. I treated with a 5 day course of tetra life guard. Fish got better, seemed less shy than he was in the 20gal so i decided to leave him in there until i needed the tank for fry. Tank has a piece of an amazon sword that i had to cut out of the 20g and 4 cryptocoryne wenditti (i know the sword is too big for that size tank, but i didnt want to waste it and it actually looks really cool in there) I did water changes once a week. I would change only about a gallon and a half (shooting for 25%) continued tests and was all good for about 3 weeks. Test came back 6ppm ammonia!!! Crazy. Immediately did a large change and double dosed with Prime to detoxify ammonia. Tested again, down to 4ppm. Next day, i tested again before getting ready to water change again and ammonia was as high as it could be. Detoxified the ammonia with Prime again. Basically battled this for the next week and did not feed food except one day mid week (5 bug bite pieces that i dropped individually and watched to make sure none hit the substrate to rot). Im confused about what is causing the spike in the first place. Its been about 5 months and ammonia is still present! Fish is fine, no gasping or ammonia burns but obviously i dont want any at all for him and im certainly not putting fry in there. I never had issues with the cycle in the larger tanks and im just bummed about this one. I dont know if its actually because its only 5g and there is less room for error or what. Any tips!!?? Thanks!!!


Ps filter is a HOB that came with kit optimized with media bag from established tank, a new sponge AND established sponge filter from 20g.

 

[Aiken Drum]

Are you also testing your other tanks? Are they showing zero ammonia?

Have you tested your tap water for ammonia?

Do you know the pH of the water on your tank?

Do you know the carbonate hardness in your tank and your tapwater? If you dont have a KH test your water company should be able to provide this for your tap water.

Is your tank water well oxygenated?

Smaller tanks do seem to take longer to cycle than larger ones, but 5 months is a long time. How long ago did you medicate the tank with tetra lifeguard?

 

[AlbanyFishGuy]

Are you also testing your other tanks? Are they showing zero ammonia?

Have you tested your tap water for ammonia?

Do you know the pH of the water on your tank?

Do you know the carbonate hardness in your tank and your tapwater? If you dont have a KH test your water company should be able to provide this for your tap water.

Is your tank water well oxygenated?

Smaller tanks do seem to take longer to cycle than larger ones, but 5 months is a long time. How long ago did you medicate the tank with tetra lifeguard?

Yes to most of that. The 20 gallon is 4 yrs or so old. The 10 is just over a year in its current use. I test the 20 once a week before weekly maintenance so that i can get an idea of how much water needs to come out based on the nitrates. Typically they will be about 30 or so ppm So generally about 25% change and then test again. The tank has always run around 10-20ppm, 0 ammonia, 0 nitrite.

The 10 gets some cleanup and new water 2x a week typically. They are juveniles and there is no substrate. They also get a ton of live baby brine so it needs a little bit more frequent care. Nitrates typically 5-10ppm, 0 ammonia, 0 nitrite.

For both 20 and 10gal PH is 6.5-7 ( always has been) , GH is about 75 (hard) KH 20-30. Id prefer at least a slightly higher KH but again that has always been the norm and never had unhealthy fish or trouble cycling. Consistancy has been my best friend with my tanks. As i mentioned the guaramis have been breeding which is always a sign of happy fish lol. I do have to drip acclimate new fish longer though to ensure a smooth transition.

I have also tested my tap water. Just recently in fact, because i thought maybe the test kit had gone bad. But no ammonia, 7PH, 75 GH, 20-30 KH.

i assume the tank oxygen is not an issue but have not tested O2. Not even sure how. BUT...all tanks have HOB filters AND sponge filters which help with surface agitation. They are also pretty heavily planted and growing lush. I have never observed signs of fish struggling to breathe or coming to the surface for air or oil slicks that typically occur in stagnant water or any of that stuff. How else could i tell? Id love to know for sure either way.

Lastly, the lifeguard was about 2 months ago now. I did 2 small water changes that week to help remove it from the water column, though i did not use activated carbon. The problem with that tank is when you change water its so easy to take out too much at once since its only 5 gal. Instead i have to really watch how much i take out unless its for a reason. The guy at my LFS ,not a Petco/Smart but a place that actually cares about and focuses on fish only, also said to be careful about too much water as Winter in NY causes the water to become overmineralized (or something similar) and can hurt the fish. He said to do small, frequent changes but to let the water sit overnight, then treat it and use normally. Something to do with the cold winters here. Idk too much about that though i had never heard of it but it cant hurt i guess.

What i do find interesting about your comment is that it made me realize i have only ever been testing ammonia nitrite and nitrate in this tank. Never did PH, KH or GH as i was focused on the cycle and seeing 0 ammonia, then 0 nitrates and finally the presence of nitrates. Would ph kh or gh affect the cycle? I havent heard anything about that. I will test it tomorrow just to see where theyre at though so thanks!

 

[Aiken Drum]

The nitrogen cycle uses both O2 and KH to convert ammonia into nitrite and nitrate. If you are low on these the ability of the nitrogen cycle has limits, and if these are low enough would stall a cycle. Over time KH will get used up if not replenished by water changes, and your cycle might eventually stall.

pH shouldnt effect your cycle, but a low pH would be an indication of low KH. What pH will effect is the toxicity of ammonia. At pH lower than 7 ammonia will mostly be in the non-toxic form of ammonium. As pH gets higher, more of the ammonia will be free ammonia which is highly toxic. At your pH of 7 and a typical tropical aquarium water temperature ammonia would need to be well in excess of 4ppm to start to worry about it, which is why your fish are fine.

Its an interesting relationship. At low KH/ pH the abilty of the nitrogen cycle to consume ammonia is limited, but at low pH the ammonia is non toxic ammonium anyway so your fish are fine. The issue comes if you do something to adjust KH levels (for instance doing a water change), which in turn pushes up pH, which makes the ammonia more toxic and kills your fish. This is what old syndrome is.

I assume your KH is ppm which is low.

 

[Aiken Drum]

A few thoughts on why your tank might not have cycled when your others are fine.

You mention high ammonia, as high as 6ppm. Its commonly thought that high ammonia will kill off the microbes responsible for your cycle. Try and do more to keep ammonia down to 0.5ppm through more frequent water changes.

As mentioned KH can be important to the nitrogen cycle. It could be that the larger tanks are replenishing KH through rocks or substrate that isnt available in the smaller tanks. Again more frequent water changes should replenish any loss of KH.

 

[Colin_T]

If you want to breed fish, either get some 2 foot aquariums or plastic storage containers and breed the adult fish in that container, then remove the adults and rear up the fry in that container.

As a general rule, you need 3 or 4 tanks for each species you are breeding if you want to breed a lot of fish. This allows each batch of eggs to have its own tank and you don't have to worry about older fish eating the new ones. If you are just casual fish breeders, then have 3 or 4 (100-200 litre) plastic storage containers and use them as required.

Gouramis have very small fry and the babies need green water and infusoria to get through the first few weeks of life. The following link has information on culturing food for baby fish and might interest you.
https://www.aquariumadvice.com/forums/f82/back-to-basics-when-breeding-fish-380381.html#post3578561

 

[AlbanyFishGuy]

If you want to breed fish, either get some 2 foot aquariums or plastic storage containers and breed the adult fish in that container, then remove the adults and rear up the fry in that container.

As a general rule, you need 3 or 4 tanks for each species you are breeding if you want to breed a lot of fish. This allows each batch of eggs to have its own tank and you don't have to worry about older fish eating the new ones. If you are just casual fish breeders, then have 3 or 4 (100-200 litre) plastic storage containers and use them as required.

Gouramis have very small fry and the babies need green water and infusoria to get through the first few weeks of life. The following link has information on culturing food for baby fish and might interest you.
https://www.aquariumadvice.com/forums/f82/back-to-basics-when-breeding-fish-380381.html#post3578561

Thanks guys so much! Both comments were super helpful! Ill have to work on getting the KH a little higher. I also clicked the link about breeding and its really interesting. We actually were planning to try infusoria cultures so its perfect timing!
Ill post the 5gallon parameters in a bit as well.

 

[AlbanyFishGuy]

Thanks guys so much! Both comments were super helpful! Ill have to work on getting the KH a little higher. I also clicked the link about breeding and its really interesting. We actually were planning to try infusoria cultures so its perfect timing!
Ill post the 5gallon parameters in a bit as well.

UPDATE:

So i just tested the 5 gallon. (Aquarium Co Op Test strip) i will do an API as well. Reads 10 nitrate, 0 ammonia, 0 nitrite, 75 GH, 0 KH, 6.5 PH, 0 chlorine

After our recent discussions, i am starting to think the reason i have been struggling to cycle is because it is cycling or close to and then crashing due to the low KH and subsequent low PH. Meaning that depending on when i test, their could be no ammonia or a ton of ammonia. I added a KH buffer to help stabalize the KH/PH. Thank you guys for your help. I know about the nitrogen cycle and have experienced many many issues over the years and fixed them. Ive enjoyed learning how to keep fish correctly and enjoy our hobby so much but this one i was stumped. I had never really given gh kh too much thought as it never seemed a problem so thanks! Ill continue to update and lets get this tank cycled together!

 

[Aiken Drum]

For info it takes about 7ppm KH to cycle out 1ppm of ammonia assuming nothing else is also absorbing ammonia like plants.

If the water in your tank is completely depleted of KH and you did a 50% water change with your 30ppm tap water that would result in 15ppm KH in your tank. A normally stocked tank would put the equivalent of 0.5 to 1.0ppm ammonia into the tank every day. So that 15ppm KH would be completely depleted again in 2 or 3 days.

 

[AlbanyFishGuy]

For info it takes about 7ppm KH to cycle out 1ppm of ammonia assuming nothing else is also absorbing ammonia like plants.

If the water in your tank is completely depleted of KH and you did a 50% water change with your 30ppm tap water that would result in 15ppm KH in your tank. A normally stocked tank would put the equivalent of 0.5 to 1.0ppm ammonia into the tank every day. So that 15ppm KH would be completely depleted again in 2 or 3 days.

Very interesting thank you. so ill be testing daily, but what do you recommend in terms of 1. Numbers to shoot for and 2. How much/often for water changes?

 

[Aiken Drum]

If you are going to be relying on water changes to replenish KH then i would just be guided by water testing and change water if ammonia hits 0.5ppm and 50% every week if you never see that. Remember KH isnt the problem, ammonia is, but at your neutral/ slightly acidic pH ammonia isnt toxic anyway.

If you are going to buffer the KH i would just get a bag of crushed coral and put it in your filter or a piece of cuttlefish bone and put it in your aquascape somewhere and call it good. This will put a steady amount of KH in the water over time and just need periodically replacing when its all disolved.

I also should say i think regardless of what ive just said about KH, your tank will cycle given time. People cycle low KH/ low pH tanks all the time. The understanding of the nitrogen cycle is incomplete and new things get discovered. The general understanding of bacteria consuming ammonia and converting it to nitrite, then other bacteria consuming nitrate and converting it to nitrate is all based on water treatment/ sewerage research, not aquariums. All the products that claim to cycle tanks are based on water treatment research etc. A recent study found that in established aquariums those previously mentioned bacteria simply arent present. The only aquariums they were found in where ones that weren't cycled and had high ammonia levels similar to what you find in water treatment plants. In established aquariums, with low (non detectable) levels of ammonia, completely different micro-organisms that arent even bacteria where found to be responsible for the nitrogen cycle. These microbes might not be reliant on KH for their carbon needs. Maybe they get their carbon from disolved CO2. They might take longer to establish than those high ammonia reliant bacteria and become more prevailant over time. We are always learning new stuff.

 

[AlbanyFishGuy]

Indeed thanks again! I had considered the crushed coral but as far as i understand, it would raise GH as well which is already pretty hard

 

[Colin_T]

Crushed coral (aka dead coral rubble), limestone, sandstone and shells are all made from calcium carbonate. They neutralise acids in the water and can raise the pH to 8.5 if there is enough shells, coral or limestone in the tank. However, you need a bit of it. These items do not normally increase the GH or KH quickly or a lot. They can raise the pH in a day or so but won't make a noticeable increase in GH or KH during the same time frame. If you want to raise the GH or KH, use a mineral salt or Rift Lake cichlid water conditioner. However, it depends on the fish you are trying to keep and you do not want a lot of minerals if you plan on keeping softwater fishes like tetras, gouramis, angelfish, Corydoras or Bettas.

Sodium bicarbonate can raise the pH and KH quickly and is cheap to buy at any supermarket (baking soda). Check the packaging because some have more than just sodium bicarbonate in and you don't want the other ingredients in the tank.