saltwater fish!!!! help!!?

Question

i have 3, 3 stripe damsels that r cycling the tank , one of them is bigger than the others and keeps chasing them away. could a damsel kill another damsel?? i testest my water the first 3 days of cycling amonie was 0 and nitite was 2.7 3 days later things r exaclty da same, its dat normal?my ph is 7.8 will it rise up after tank is cycle????also ok not to have a air pump,and powerheads??can i have a blue tang in 20 gallon tank? i want to have a pair of occularis clows,a yellow watchman goby and blue tang.

i have 20 gallon tank with crust coral,bio-wheel filter, will get a protein skimmer after tank cycled.ph 7.8, 1.023,80F. help me ,n thank you so much for your time.

Answer 1

Yes a damsel can kill another. These are territorial fish, and the largest is claiming the tank as its territory.

You need to do a water change to bring down your nitrites. you want to keep this below 1 at all times, preferably below 0.5. Until the bacteria are established to convert the nitrite to nitrate, you're the only one who can lower it. It's not a normal cycle either, since you apparently didn't have ammonia. Did you use live rock in the tank? If so, this may have had enough bacteria to convert the ammonia to nitrite, but it should also have the bacteria to convert to nitrate as well. You might try having your store check your results by having them test a sample of your water.

The pH won't change when the tank is cycled. The 7.8 level is what you'll have, since this is all the higher the coral/aragonite substarte can raise it on its own. I have the same problem in my tanks, and I've had to use kalkwasser to bring it up to 8.2 where it should be.

It's okay not to have airpumps, since they don't do that much for a saltwater tank. If you only have fish, you shouldn't need powerheads unless you have a lot of live rock. The powerheads keep the water moving so wastes and debris don't build up behind the rock.

In a 20 gallon tank, a blue tang (and really ANY tang) is out. The blue will get about a foot or more long as an adult, and there isn't room for it. You'd need a tank of at least 90 gallons or larger to have one. It's okay for the ocellaris, but if they decide to spawn, they may bully the goby. You should use a good bit of live rock so it would have hiding space, and unless your tank is a 20 long, adding any third fish may be pushing it for the clowns.

Answer 2

Damsels are agressive fish and will fight.
Your nitrite cycle is just starting, be patient, it will rise and then fall to 0, then your Nitrate will rise and fall.
Your ph is low, you can raise and stablize it naturally by adding some live rock.
I would add a MaxiJet 1200 powerhead for more flow inside the tank.
I would not recommend a blue tang for that size of tank, it will outgrow a 20gal.
The other 3 fish are a good choice BUT make sure that you get rid of the Damsels after your tank has cycled, they will probably kill the other fish.
ALWAYS add fish slowly, I would add the 2 clowns then wait a few weeks before adding any other fish.
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http://www.liveaquaria.com/product/prod_Display.cfm?pCatId=228

Answer 3

if i was you i would get the protein skimmer before i would get the fish