New Tank Help

[Nero_Vipus]

My first tropical fish 20 gallon tank and has been running for a week. I am an amateur that has done a lot of research but can't find solutions to the following problems:
Just added 4 zebra danios and 2 panda cory's
Now for the questions:

1. I have gravel. Researched that it can damage the cory's 'whiskers'. Should I buy some sand to add into a section of the tank or layer on top of the gravel? Been 12 hours since they were added and they are very active. Also very small and cute, under 1/2 an inch.

2. 3 of the zebra's are very active just like the research promised. The 4th has been hiding the entire time and not moving much. It is not schooling with its siblings. The danios seem mature and almost fully grown. Why is this 4th one being so inactive and shy? How concerned should I be and what possibilities am I looking at? Is it stressed to the new environment and not adapted as well as the others?

3. I don't plan on increasing the fish population much. At most I plan on adding 2 more danios and a stand alone fish that is peaceful and can be happy without others of its kind. Will my danios be just as happy if I get different types? Like leopard danios? Will they not school as well? And for my singular fish, any recommendations? I was thinking something like a rainbow shark but maybe not as big when full grown (5 inches).

Thanks!

 

[nic1]

Hello
So, has your tank been running for a week with fish or has it just been running for a week.... Did you cycle the tank before you put the fish in?
1) your corydoras would prefer sand as the gravel could have sharp edges and damage their delicate barbels, Cory's love to dig and move stuff around exploring , mine sometimes swim to the top of the tank and dive bomb in to the sand.... If you put sand over the top of the gravel it will eventually work it's way all past the gravel and sit on the bottom of the tank, so no, it's best not to layer the gravel. You can section a large area off for them like you mentioned.
2) the 4th danio is probably just getting used to the new environment and hiding is pretty common until they get their bearings. He should be fine in a couple of days.
The reason why I mentioned cycling the tank is because this can also have an effect on your fishes behaviour.
3) you can get other types of danios to mix as long as there are others of his kind.
Is your water soft or hard? What are the parameters, can't really answer the last section as we need to know what type of water you have

 

[Nero_Vipus]

Thanks for the insight,

The tank has been running for a week so not a full cycle. The fish were just introduced. Zebras seem to be very hardy with cycling so no problem there. My LFS fish 'expert' recommended I got the cats now instead of when I originally planned at a later date because they would eat any of the left over food. Water hardness in my opinion is perfect and sits around 10. My LFS, which has a good reputation with my friends and their fish, tested my water 2 days ago and said the water wasn't poisonous and good to go. I was trying to research a peaceful non-schooling fish that I could add to the tank but I only got mixed results and the best idea I have is a guppy although I don't know how well one would be since they do seem to like to school.

 

[Lillefishy]

You have a few issues here, first being the filter isn't cycled so you'll need a test kit & probably daily water changes so the fishes waste doesn't poison them.
Corys really need to be on sand as they sift sand through their gills for particles of food, although they will eat any leftover food that hits the bottom they need feeding in their own right. A good catfish pellet & frozen or live bloodworm, brine shrimp daphnia etc as they are virtually carnivores, they should also be kept in groups of 6+
I wouldn't add any more fish until your filter is cycled, when you get your test kit post the results so people here can help you with any problems

 

[nic1]

I wouldnt get anymore fish, not just yet.
As suggested you need to get a water testing kit. Your water may be perfect now but as it hasnt cycled properly you will encounter some problems along the way.
The purpose of the testing kit is to test for any spikes that can kill your fish, that is an indication that you need to do a water change.
fish in cycling in my opinion is so cruel, and the expert fish man is only thinking of profit, he doesnt care about what happens to your fish as afterall they arent in his tank, but he has a happy boss who has a pocket full of cash.
im not having a pop here as it isnt your fault, so what I suggest is holding off buying anymore fish, do water changes little and often, invest in a water testing kit, try and get some benefical bacteria or filter media from the fish shop, there are also some filter boosting products you can pick up,
record your test results and monitor them if you need help with it post the results here,
guppies will breed and breed so you will have to find ways of rehoming or controlling them. Please read about fish in cycling just in case you run into problems.

 

[Nero_Vipus]

The suggestions are appreciated.

I do realize I have made some beginner mistakes. I will record what happens over the next few weeks for anyone else's benefit. So a list of what I have to do:
-add sand for Cory's (how urgent is this matter?)
-would adding a live plant help at all with cycling? (Any plant type suggestions?)
-I was looking at getting bloodworms but it looks like my danios eat them to, so should I look for Cory cat food that danios won't bother? Or can they share?
-how much water should I change per day (%) in a 20 gallon?
-I haven't heard of beneficial bacteria before and I don't know what a media filter is. To my understanding they help with the cycle?

Edit: can I mix sand with gravel? Or just make half of my tank sand? Will the Cory's be smart enough to stick to that part of the tank?

 

[b3cca]

Of course the water your LFS tested was fine and not poisonous, that's because nothing had been in the tank to produce any waste.
 
Filter media is the bio things (sponge, noodles) inside your filter where the beneficial bacteria live and are essential to having a stable environment. You say you have fish keeping friends then your best thing to start with would be to get some established media from them to put into your tank.
 
If you think Zebras are hardy and won't mind high Ammonia or Nitrites then you're very wrong. Please read up on ammonia poisoning and brown blood disease to understand just what they will go through if you don't keep on top of things.
 
You are simply starting a fish in cycle is all, It's frowned upon here but it's not a major problem if done correctly so please read the articles at the top of this page about Nitrogen cycle and how to cycle a tank.
All you need is a good liquid test kit, patience and the time to do many partial water changes as and when needed (i'e as soon as you see ammonia or nitrite on test kit)