[neurozy]

I just started my first saltwater tank:
10galon salt water tank w/
1.crushed coral substrate;
2.one tufa rock;
3.artificial plants;
4.power filter;
5.thermometer;
6.hood w/ light;
7.bubbling w/airstone;

Currently, there're 2 bluefin demsel fishes in the tank for 2 weeks;
test water every 2 days;
Ph=8.2;
NH3/NH4: 0.25 ppm;
NO2: 0;
NO3: 0;
the watertest result has been like this since the fishes were added, even though I add fluid bacteria every 2 days.

I tried to add some dry bactera a couple of days ago, and finally that made my tank messed up. There're some dark brown bacterial plaque growing on the tufa, and even on some substrate sands. The bacterial plaques are growing these days, and today I found some new green plaques on the tufa.

Does anyone know what the hell those dark brown bacterial plaque is? Normal alga, or some bad bacterials? I added the two fishes to trigger N-cycle as a Petco guy told me, but seems I can't get those NH3/NH4 gone. Any ideas please?

Thanks a lot!

[pyromaniac398]

Picture is a little hard to tell but more than likely it is cyano bacteria. Cyano is usually a sign of not enough flow and is easily fixed by adding a power head or two. When you do your next water change try to siphon as much of the cyano out as you can, it should come up easy.

[ianizaguirre]

no ofence but that dose not look like a saltwater tank even though it is try putting in live rock and live sand and a power head

[neurozy]

Thanks, guys!
I guess I need to start with a powerhead to get the tank work...

[Mr_X]

cyanobacteria is fueled by excess nutrients.
you will need to export nutrients better, to starve it. increasing the flow will visually help, but take it's food away, and you'
ll be better off.

what do you use to hold your beneficial bacteria?
do you have bio balls or some sort of media somewhere?

most marine tank keepers use live rock to hold bacteria. it's a very effective form of filtration.
some say 1 pound per gallon will do the trick. i say, the most you can fit in the tank, and it still be pleasing to the eye.

[carmanimports]

what light are u using cuz i see that the tank looks to be fresh water setup turned salt try puting a 50/50 bulb in and raising it just a bit and that will go away in a week or so.

[unclejed]

I tend to disagree with everyone leaning toward cyno. It looks to me as a natural brown diatom algae. You will and should get this and some green as the tank cycles. This is normal and a sign the tank is healthy. An added power head is a great idea for more current. A Koralia nano is better for current mimicking and distribution. Your tank is looking good. Be patient and let the tank cycle completely followed by a couple of months of allowing the tank to season. only change out about 1/3 of the water every 2 weeks and add more bacteria. The bacteria you add is "good" bacteria and has nothing to do with the brown diatoms.

[spanko]

The brown is definitely diatoms. Your tank has not cycled yet. What you are seeing is the natural progression of a cycle. The bacteria you are adding is doing little to nothing but wasting your money. The tank will cycle now that you have the fish in there. This was not a good move but was the accepted method years ago to cycle a tank. Leave the tank alone except for weekly water changes of 10%.Also clean\replace and filter material you have at that time. You would benefit by adding some more tufa to the tank. The more surface area you have the better bio filtration you will have.
You are moving in a direction that has worked in the past but is not now the accepted norm for starting a tank. The fish will experience a rise in ammonia and nitrites that at the very least will be extremely uncomfortable for them and at the most will kill them.
Chastising you for what you are doing is an after the fact thing now that it is done. Get yourself a good reef book and read it a few times. Keep posting here and asking questions and you will get through this and hopefully not get discouraged and give up. Be ready for some tough times though. Also if you are doing so stop using tap water. Get RO from the fish store or Walmart of distilled water from the grocery store. Make sure you top off the tank with RO or Distilled fresh water to maintain your salinity.

[neurozy]

Finally...my two bluefin damselfishes died .. feel very sad.

Actually a tufa rock and crushed coral substrate are used to hold bacteria in my tank. As carmanimports mentioned, the light that I'm using is a regular fluorescence one, not 50/50. Not sure whether I need a 50/50 bulb for this fish-only tank?

I think I may have bothered them too much. Here's what I did to get rid of those alga.:

After crazy growing of those bacteria, I did full change of the water, washed everything in the tank and boiled the tufa and substrate sands. ( I think Mr_X is right about excess nutrients. There're a lot of food debris in the substrate sands. I gave them too much food.) Then refilled the tank with water, added AquaSafe and salt. After the PH, salt density and temperature were all set, I added some liquid bacteria and then the two fishes.

Everything was ok for a couple of days. I reduced feeding them. Then I got my maxi-jet powerheader and another toy for bubbling, and hooked them with my tank. Initially, my two bluefins were ok, but not as active as before. They ate some food as usual.

However, two days later, one of them looked weird. It was like sleeping, lack of strength (floating with water flow, and sometimes hiting the artificial plants in the tank), no interest in food. Its yellow back turned dark a little bit (see picture). Then I tested the water, and everything seems ok. Ph=8.2; NH3/NH4: 0;NO2: 0;NO3: 0;

I was guessing something toxic from the new toy or the powerheader that I got, or the fish just didn't like the roily water. So I stopped the water fllow and fully changed the water again. But still, they died one after one after another day.

They were good before even the tank was contaminated with huge amount of alga. Really hardy, but can't stay this time.
Don't know whether it's because I gave them too much stress, the tank changed too much during these two weeks. Or something toxic in my tank. I'm thinking to let the tank be w/o any fishes for a while.. kind of fear to add any fishes right now.

Very tough time, still a long way to go for me, but I think I'll keep going. I really appreciat you guys' nice comments. I'll keep learning from here and then start my new fishes.