I plan to put 5 corys, 7 neon tetras and 1 dwarf gourami in my 20 gal cycled tank (freshly cycled).
Corys (small ones such as Sterba's or Panda) are bottom feeders, the rest - middle fish. I know that 5+7+1 might be too a bit much for 20 gallons, but I hope Neon tetras will have little impact on aquarium NH3 cycle.
One center piece, a group of school fish, and a group of bottom feeders.
Personally, I'd increase the number of corydoras catfish to 6. The more cory, the more active they will become. They are very cute when active. Not so cute when they are shy and hide all the time. Yes, I would choose the smaller species. Some of them can be 3.5" long which are a little big for a 20-gallon.
You may also increase the number of Neon Tetra to 10. Or get 10 Cardinal Tetra instead since they do not get the infamous Neon Tetra disease which has a high death rate.
One dwarf gourami is great as the center piece if you get it from a high quality fish place. Many dwarf gourami from cheap sources are also short lived.
A fully cycled 20-gallon fish tank should be able to handle 6+10+1 small tropical fish no problem, as long as you do not overfeed them.
For the top / middle level fish, I'd feed them New Life Spectrum pellets. You only need to feed them as much as they can finish all of it within 30 seconds. For the Corydoras, the best food is Hikia algae wafer, a single wafer per day is enough.
By the way, what aquarium filter are you using? The filter efficiency matters when it comes to how many fish you can have in the aquarium.
I'm using Fluval C3 Power Filter, the filter is at the top right corner of the tank, water intake tube is extended to left bottom corner of the tank, this configuration ensures good water circulation. Fluval C3 is rated 153 gallon/hour. I'm not using carb filter, this should also improve water flow.
I think the main concern/limit is biological filtration, Fluval C3 does not have a huge pocket for C-nodes (surface/place for bacteria colonization). But I don't plan to change tank equipment, this is my first tank with fish and plants (have a mix of Anuibas + Amazon Sword) and at this point I plan to adjust fish type and population to tank capabilities.
Quote:>Personally, I'd increase the number of corydoras catfish to 6. The more cory, the more active they will become. They are very cute when active. Not so cute when they are shy and hide all the time. Yes, I would choose the smaller species. Some of them can be 3.5" long which are a little big for a 20-gallon.
What kind of small corydoras would you recommend?
Quote:>You may also increase the number of Neon Tetra to 10. Or get 10 Cardinal Tetra instead since they do not get the infamous Neon Tetra disease which has a high death rate
My kid is in love with Neon Tetra so this one is a must
Quote:>One dwarf gourami is great as the center piece if you get it from a high quality fish place.
Could you recommend way to recognize such high quality fish place from other places? So far I've been looking for fish at PetSmart mainly, one store (out of 3 I visited) has lively Tetras, and some selection of Corys. But I should agree that selection of Gouramis/Dwarf Gouramis is not great. Is there any way to shop online? Save
05-31-2016, 08:14 AM, (This post was last modified: 05-31-2016, 08:17 AM by delta678.)
All cardinal/Neon tetras, Corydoras and Gourami require pH to be 7.0-7.5 max.
My tap water is really soft, it's 1-2 KH, 1-2 GH and 9.4 pH. So in order to keep the fish I need to target pH of 7.
My plan is to use combination of Seachem Alcaline buffer and Acid buffer, this buffers are plant compatible. First get amount of Alcaline buffer to target KH of 3-4, then add/mix Acid buffer to target water pH of 7.
Thor, could you comment on the plan and suggest an alternative.
(05-31-2016, 04:05 AM)delta678 Wrote: Thank you for the suggestion, Thor
I'm using Fluval C3 Power Filter, the filter is at the top right corner of the tank, water intake tube is extended to left bottom corner of the tank, this configuration ensures good water circulation. Fluval C3 is rated 153 gallon/hour. I'm not using carb filter, this should also improve water flow.
I think the main concern/limit is biological filtration, Fluval C3 does not have a huge pocket for C-nodes (surface/place for bacteria colonization). But I don't plan to change tank equipment, this is my first tank with fish and plants (have a mix of Anuibas + Amazon Sword) and at this point I plan to adjust fish type and population to tank capabilities.
What kind of small corydoras would you recommend?
My kid is in love with Neon Tetra so this one is a must
Could you recommend way to recognize such high quality fish place from other places? So far I've been looking for fish at PetSmart mainly, one store (out of 3 I visited) has lively Tetras, and some selection of Corys. But I should agree that selection of Gouramis/Dwarf Gouramis is not great. Is there any way to shop online? Save
Some species of corydoras catfish are 2~2.5" long, some others can be up to 3.5" or even slightly larger.
The smaller ones are False Julii Cory Cat, and Palespotted cory cat. They are usually about 2" long at full adult size.
Panda Corydoras catfish, Albino Aeneus Cory Cat, Peppered cory cat, Elegans Cory Cat, Skunk Cory Cat, Swartz's Cory Cat, Nanus Cory Cat, are around 2.5" long at full size.
Neon Tetra and Cardinal Tetra look very similar. Both are blue with one red strip at the bottom. The only tiny difference is the Neon Tetra's red strip only goes half way cross the belly, while the Cardinal Tetra's red strip goes all the way. Most people won't even tell the difference.
Check out the photos to see for yourself.
Neon Tetra
Cardinal Tetra
See? They are in fact related species. Both are school fish, both are tetra. Cardinal Tetra is slightly bigger than Neon Tetra.
You can buy high quality fish from liveaquaria. I have shopped from them with good experience. If you decide to shop from them, you might as well order all of your fish at once to make the shipping cost worthwhile. Do not overstock your fish tank just because there is free shipping over a certain amount.
(05-31-2016, 08:14 AM)delta678 Wrote: I also have a question on pH control.
All cardinal/Neon tetras, Corydoras and Gourami require pH to be 7.0-7.5 max.
My tap water is really soft, it's 1-2 KH, 1-2 GH and 9.4 pH. So in order to keep the fish I need to target pH of 7.
My plan is to use combination of Seachem Alcaline buffer and Acid buffer, this buffers are plant compatible. First get amount of Alcaline buffer to target KH of 3-4, then add/mix Acid buffer to target water pH of 7.
Thor, could you comment on the plan and suggest an alternative.
High PH can be adapted by fish easily if you give them time when first introduce them to your fish tank. Just slowly add the tank water to the plastic bag of the fish little by little. The process usually takes me 2~3 hours. Yes, I am extremely careful when it comes to introducing new fish to the aquarium. They will be able to handle it.
Water hardness on the other hand might be harder to adapt if the difference is too great.
I do not recommend to mess with water perimeters with chemical products. Once you have started to use them, you have to always use them in exact amount in order to give fish the same water every time. One mistake in mixing, you might kill your fish. Basically, never mess with water PH or hardness. The only chemical compound you need for a healthy aquarium is the water conditioner.
(05-31-2016, 05:06 PM)Thor Wrote: Basically, never mess with water PH or hardness. The only chemical compound you need for a healthy aquarium is the water conditioner.
What about keeping KH at least 3-4 degrees? My tap water is around 1-2 KH degrees, this means that _potentially_ pH might largely fluctuate, because (for example) of different CO2/O2 input/output balance for plants; the balance is different between daytime and nighttime.
Small PH fluctuation is not much of a concern without the change in water hardness at the same time. My tap water is also very soft. I do not see large swing in PH aside the time during fishless cycling with the buildup of high concentration of nitrate. I have used CO2 injection too.
By the way, I forgot to mention something from one of your earlier posts. You have said the filter media is quite small. To partially solve this issue, you can use more filter media or even just a piece of sponge in the place of carbon pad. In fact, a lot of us had removed the activated carbon pad, and in its place we use more of the filter media required for biological filtration. You can also use a small sponge filter at the intake of your filter to increase biological filtration. As a bonus, the sponge filter on the intake will block most of the debris. It can keep your filter clean, thus lower the maintenance requirement on the filter itself.
Thank you on advice to use chemical filter pocket for additional biological filter media, Thor
Frankly speaking I still did not get the idea how you can "train/adapt" new fish to your aquarium water.
My tap water has 9.4-9.5 pH, there is no way any community fish will tolerate such high pH. At best they can survive up to 8-8.5 pH.
So regardless of how long I'm going to extend period of adjusting transport container water to the water in my tank the fish will die, it just ca not arrive at the destination - to "hot" for them
Mixing RO water with the tap water is also not helping. Tap water has 9.4 pH, RO (my home RO system) water pH is 6.54. When I mix 50% tap with 50% RO I get the mix with pH 8.8 (it's not 6.54+0.3=6.84 pH as you might expect) because tap water has KH around 1-2 so some H+ are consumed.
I believe injecting CO2 is one of the solution. But personally I'm inclining to add small amount of mix of Acid buffer (carbonic acid) and Alcaline buffer (sodium bicarbonate), this way I can target any pH in the range of 6.5 to 9.4
If you have RO unit at home, then you can use 100% RO water. The problem with RO water is almost all of its minerals (water buffer) had been stripped. Any slight change can swing its PH by huge amount. What you need is to add the mineral back to restore its water buffer. The product you need is Seachem equilibrium. Be very careful on the instruction. It is still a lot simpler and safer than trying to mess with tap water.
Added 6 Sterbai Corydoras and 5 Cardinal Tetras on Sat, then added more 5 Cardinal Tetras on Sun.
Corys are doing fine - exploring the whole tank, eating Hikia algae wafer and giving me a lot of joy
On the other hand Tetras are worrying me, since they stay in the corner and do not eat at all. I'm using New Life Spectrum Sinking Pellet, initially it floats at the surface for some time, then it is taken to the middle of the tank with the filter stream. Today is Tue so Tetras should be hungry but they are not interested in food.
Another trouble comes from the plants - they started to cover with black/brown spots. I can't remove the spots from the leaves so I guess it's not algae. NH3 and NO2 is 0, NO3 is around 5-10 ppm, pH is 7.0- 7.4, temp 79-80 F. I keep KH around 1-2 and GH around 5-6, this should be acceptable by both fish and plants. I guess there should be a reason for the spots on the leaves.
Since the Corydoras catfish are doing fine, and you are getting good readings on the water, it should only mean one thing if the Cardinal Tetra are not active - They have too few in number. So they are stressed. 5~6 is the minimal requirement for a school. The more the better. When I added over a dozen of them to a new tank, usually they are immediately happy to be in the new aquarium. A bigger group will bring out their natural behaviors. It is the same for all school fish.
As for the plants, they are clearly not doing well. They need nutrients (not only nitrate, but they also need various minerals), adequate lights, and CO2 to thrive. They usually do not do well with regular gravel. It is why good substrate rich in minerals is so important for a planted aquarium. There are some commercially available aquarium fertilizers you might want to check into. I have used Flourish Tabs in the past. Not sure how effective it was since I already had mineral rich Eco-complete substrate.
I have 10 tetras, that's above recommended number of 8. I'm adding Equilibrium as a mineral source for plants.
Thank you for the Seachem Flourish tabs, I'll try it
Is it reasonable to change the substrate while the fish is in the tank? Or should I move the fish to the temporary place first (no filter though)?
Sorry, I did not read your post correctly. I thought you were going to add another 5 Cardinal Tetra the next Sunday.
Something is stressing them. A few things you need to check into.
For example, is the water current too strong? Is the heat from the heater evenly distributed? What is your water temperature anyway?
I'd also recommend to add a background to cover up the back of your fish tank. Add more hiding places can also be helpful. Fish are more likely to act normal when they feel safe.
By the way, haven't they eaten anything at all since you got them? Always stay in the corner?
Changing substrate is a big rearrangement since you have already added the fish. You can actually get some new substrate and mix it up with the old gravel if you wish.
If you decide to switch the substrate completely, it can still be done if you do it carefully and quickly. You need to get everything prepared first. Including the new substrate. Yes, remove fish first is needed. You can temporary transfer them to a bucket or another fish tank. Let the filter run on whatever container you use to house them. Do not forget the heater and the air pump either. Especially the filter media, it must be wet the whole time even if you decide not to use it during the transfer... or you might risk losing the bacteria colonies.
Actually if I were to do it, it would be in this order.
1. Turn off all electronics first.
2. Drain the aquarium water to another fish tank or a water bucket (their temporary home). Leave 30% maybe a little less water in the main aquarium.
3. Transfer the fish to their temporary home.
4. Drain more water to almost just the substrate is left.
5. Remove the substrate.
6. Add the new substrate.
7. Add most of the water back first.
8. Fill the tank back up with new treated water.
9. Add the fish back (but do it the same way as you have just got them).
Actually before you switch the substrate, you might want to try other things first. It is a lot of work and a big decision indeed. Even after you have bought the new substrate, it might not guarantee to fix the problem. Nutrients, lights, CO2, every one of them is important.
As for now, the fish is your priority. Get them to act normal first before doing something dramatic with your aquarium.
(06-08-2016, 05:50 PM)Thor Wrote: For example, is the water current too strong? Is the heat from the heater evenly distributed? What is your water temperature anyway?
By the way, haven't they eaten anything at all since you got them? Always stay in the corner?
Please show me a photo or two of the situation.
Thank you for the quick reply, Thor
I have black gravel and yellowish gravels corners/parts, the heater is above the black and the filter output is above the yellowish. Tetras stay above the black gravel - closer to the heater, I think they feel safer this way. I don't think current is too strong. I have one heater but the last couple of days the heater is almost off all the time - outside temperature is above 80
Few fish try to bite the pellet passing by but do it only once, not trying to follow the food. Also I've put black sheet of paper on the wall behind the tank. When the Corys are eating then the Tetras swimming closer to the Corys, overall they just hang in the corner, even at the night time, when the lights are out.
I'll post a video when I get good daytime light.
06-08-2016, 06:43 PM, (This post was last modified: 06-08-2016, 06:45 PM by delta678.)
I see what you mean.
The school of corydoras catfish is definitely a great sight to watch. The Cardinal Tetra are not feeling well to come out of the corner. It is likely they do not feel safe enough. There is also the possibility that they like the warmer corner. The first thing I would do is to move the heater away from the corner. It should be placed toward the middle of the back. Relocate the tree house decoration to the corner to take over that part of the free space might force them to come out. You might want to try it too.
By the way, what is the black tube at the bottom below the heater? Is it the intake of the filter?
It is unusual to see different substrates in different areas of the same fish tank. Some reports say some fish might act less timidly with darker substrate. It can be read as some fish feel safer with darker substrate. It is possible the brighter substrate in your aquarium is making the Cardinals feel unsafe. As a result, they hide in a corner over the darker substrate when you have given them a choice. You can mix up the two substrates to have the entire fish tank floor look the same. Increase the number of Cardinal Tetra might help.
You might want to wait a few more days first. There is nothing to worry about fish not eating for a few days. They can live for weeks without food. Give them some time to get used to their new home. If the problem does not go away by a week mark, then you can try some of the suggestions.
Ram, Thor:
Thank you for the advice about fish. I've shuffled plants and equipment inside the tank, the outcome was pretty much the same - shy Tetras in the corner. But with every day they are more interested in food and moving toward the aquarium front during the feeding time. I see that pellets are consumed so I have no worries about starved fish. I'm thinking about changing or mixing the substrate.
The biggest problem right now is poor health of the plants - big black spots on leaves, brown and sludgy leaves. I think I have red algae so need to adjust the lighting first.
What do you think bout UV treatment of the water? Will it improve the plants health and look?
Black and brown spots on the leaves, most of the time it mean deficiency in minerals and other nutrients. If it is indeed black spot algae, it is something completely different. Lights not strong enough can cause plants become weak too.
I wouldn't jump onto UV equipment. A long time ago I almost bought it myself to treat both algae and parasites, but I stopped my urge and I am not missing it. Just another piece of non-mandatory equipment to burn your money with. There are many ways to control algae at the source, including limit the time of the lights exposure to even fewer hours, and keep the organic waste low by doing partial water changes.
Before you buy more substrate, mix them first to see if the situation improve. Sometimes the fish do not like the reflected light from lighter color substrate from what I have heard.
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20 gal tank - good mix of community fish ?
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