New tank help

[sg88]

Hi all,
I am a newbie in marine aquariums:
Staring a new marine aquarium and have had 4 fish die during set up. Appreciate ideas.

Details: Aqueon 15 gallon column tank, filter Fluval G3 (185gph flow rate). FOWLR. Substrate: live sand from local beach (oops...I have seen two small crabs <1 inch, something that looks like a bristle worm but is gray to colorless, not red like the pictures I see, and a few anemone-like things that have died off). Water is seawater from community outlet specifically placed for hobbyists. Temp of tank 78-84 Fahrenheit initially, now rock solid at 78.5 during last fish (thermoelectric chiller). First fish from local big-box pet store (Fiji Damsel, died in under 24 hrs. Water pristine low ammonia, 0 nitrite, 0 nitrate. Second and third blue-green Chromis from very reputable marine aquarium store died in 2-3 days each and I never saw them eat any of the marine flakes I provided. Final fish (same Chromis) died at 4 days in the tank, having gorged so quickly on mysis shrimp I fed him for two days that I gave him a fasting day because I was scarred he was overeating (by my overfeeding)...parameters were all acceptable, with Nitrite reaching 1.0 ppm between fish 3 and 4, but going to just detectable at .25 ppm after a water change prior to introducing the last fish. I did find the last fish the day before he died in a deep crevice in my rock with fins moving but uninterested in coming out for food I added. I thought he might have been stuck but checked again and he had reversed orientation. Next morning he was dead on the sand. No claw marks to suggest the little crabs had gotten him.
So I have read on the forum that the worm is not the likely culprit. Ammonia peaked at 2 ppm between fish 2 and 3 and has been 0 since. All parameters were good for fish 1 and 4. Salinity 1.020-1.023. pH 7.8-8.0.
I have successfully cycled and maintained planted freshwater aquaria, but not sure what I am doing wrong with this first try at salt water.

 

[jay0705]

First off, HORRIBLE idea to use fish to cycle sw. Use live rock. 2nd a 15 gallon is really small for sw. Maybe 2 fish max

 

[sg88]

I get it that, but was convinced that there wasn’t much cycling to be done since the seawater, substrate and rock were right out of the nearby water provided by a friend who has a number of tanks that he has done this way. With just the little crabs and such ammonia, nitrite and nitrate were all undetectable. With the addition of the fish (never more than one at any one time), I did get the expected nitrite, then nitrate spikes that responded to water changes.

So I am still stuck with what killed the fish. I now have a cycled tank without a fish...not wanting to kill any more, but maybe now I am hurting the bacteria by not providing bioload.

I realize that this is a small tank but it is all I have room for at this time. Final tank plan is for 2 or three fish: a bottom dweller like a lawnmower Blenny, a mid level fish like a clown, and maybe an upper level fish (I have been told the blue green Chromis tend to like the top of the tank) but possibly just two fish. While the volume of my tank is small it is 20” tall so it seems that 2 or 3 fish could stake out their own space. My live rock is stacked to reach a few inches from the surface.

 

[beaslbob]

If you have ever had planted FW tank, then you already know how easy they are to maintain because of the balanced and stable environment the plants provide.

In saltwater tank the same exact thing applies for the same exact reasons. Only there are basically no actually plants with circulation system in saltwater. What there are is macro algae which are algae that are organized and kinda sorta look like plants.

What I do and recommend you do is to add macro algae to balance out and stabilize the operation. I put them in right from the start but adding them later is good also. I recommend chaetomorphia (brillo pad). One good thing to do is use 1/4" plastic grid (egg crate) used as lighting diffusers in dropped ceilings. a 4'x2' section if ~ $12 or so from building supply stores. Just cut to size and put a section 2-3" from side or back glass. Some back/side horizontal lighting would help also. Then put the chaetomorphia between the glass on the egg crate.

And most of all best tank ever. Sorry you had a bad initial experience.


still that's just my .02

 

[sg88]

If you have ever had planted FW tank, then you already know how easy they are to maintain because of the balanced and stable environment the plants provide.

I saltwater tank the same exact thing applies for the same exact reasons. Only there are basically no actually plants with circulation system in saltwater. What there are is macro algae which are algae that are organized and kinda sorta look like plants.

What I do and recommend you do is to add macro algae to balance out and stabilize the operation. I put them in right from the start but adding them later is good also. I recommend chaetomorphia (brillo pad). One good thing to do is use 1/4" plastic grid (egg crate) used as lighting diffusers in dropped ceilings. a 4'x2' section if ~ $12 or so from building supply stores. Just cut to size and put a section 2-3" from side or back glass. Some back/side horizontal lighting would help also. Then put the chaetomorphia between the glass on the egg crate.

And most of all best tank ever. Sorry you had a bad initial experience.


still that's just my .02

Thanks...it is interesting that we work so hard in FW tanks to avoid algae...I will have to look into that. Guy at my local fish store suggested that I need to have a reasonable amount of established algae to support a lawnmower blenny, which I would like to have in my tank. Not sure if he is talking about micro algae like hair algae or macro algae like chaetomorphia. Quick look online suggests that a blenny might eat either.

 

[lmforbis]

A 15 gallon isn’t big enough to support a lawnmower blenny. You will be seriously limited in a 15 gallon.

To be honest I wouldn’t use natural seawater. It can bring in disease and pests. The salt mixes have higher levels of trace minerals that get depleted in a tank. Live sand from the beach has similar issues.

Look into a quarantine system while you are cycling your tank. It is important to quarantine all saltwater fish before they go into your tank. It just takes 1 sick fish to kill off everything then you need to let the tank sit empty for a long time for the parasite to die off. You can’t treat a SW tank for diseases the way you can a freshwater system.

 

[Jesterrace]

Yeah, I definitely wouldn't be using local beach sand, seawater, etc. Parasites, waste and other issues are a real factor in a small captive environment and they can easily kill all life in a tank.