Lost my Damsel fish today

[Scubakid]

I was given my 20g aquarium in November for my birthday. Before introducing any fish I balanced the water and let it set with live sand for nearly 2 weeks. I then added 2 pieces of live rock - doing 10% tank changes each week. All at the advice of two different aquarium stores in the town where I live. The advice was pretty consistent from both although one is a chain and one a very specialized marine aquarium store.

At the advice of the chain store, I added a white Damsel and it has been doing well for the last two weeks. They suggested I do this to "test" my water before investing in a more expensive fish? This is why I took home the Damsel.

I waited the two weeks then added the 3 hermits about one week ago along w/ a 6 line Wrasse. The Wrasse is doing great and swims all over the tank until night when he hides/sleeps in one of the tunnels I made him w/ live rock. He and the Damsel seemed to be doing well together and leaving each other alone. I watch them a lot and have never seen them fight - maybe just a quick run in at feeding time.

Today, during my weekly 10% salt water change, my Damsel started swimming sideways. Once it began lying on its side on the sand, the Wrasse began to pick at it so I took it out and put it in a separate, small tank. It died about 20 mins later but not at the hands of the wrasse.. Could it be my water? My level is in the green as is the tempurature. I even buy pre made salt water from my local aquarium who offer this as a service so the balance is correct.

Is my wrasse at fault, my fault? Before I introduce ANY more new fish, my parents want me to try to ask some questions and to understand why the Damsel may have died so we can fix the problem.

Again, the wrasse is thriving and healthy appearing. He seems to be having fun in there. Really appreciate any guidance or advice from the more experienced aquarium people on this forum. Thank you,

[Maxxumless]

I highly recommend you buy this at your local bookstore or order it online: Marine Reef Aquarium Handbook. Most often you shouldn't listen to your local fish stores - they're businesses and their main goal is to sell you things. Even if they are well intentioned, they really don't have the time nor the responsibility of teaching you how to keep a saltwater aquarium. The book only costs like $1 used and a few days to read and it will help you WAY more than any store.

[camblonie]

How did the damsel look? Were parts missing, dusty looking, white spots?

[lonzoencho]

Could you be more specific on your levels? Was the stomach pinched on the damsel? I doubt it was the wrasse's fault though it is a possibility depending on the species

[FishAddict87]

How many pounds of rock do you have? Recommended is 1 pound per gallon.

[Scubakid]

Thank you Maxxumless - I will get that book for sure.

[FTDelta]

Sounds like you're going about setting your first SW tank all wrong. Another book you can find is The Conscientious Marine Aquarist by Robert Fenner. Read and research everything FIRST before going any further.

[Scubakid]

I only have 2.5 lbs of live rock or so FishAddict87. Thank you. I will be going to store tomorrow and will pick up some more. I think we are going to take a water sample to be tested also.
camblonie the Damsel looked fine - a bit darker and I noticed the night before it was not eating as aggressively as it usually does. A flake would float by him and it wouldn't even go for it.
In the morning, after I did the 10% water change, I did notice what looked like a dark line forming just between its eyes across top of head. The wrasse was nipping at it only when it was lying there - Had never seen them really bite each other until then. That was when I took the Damsel out to another small tank.

[FTDelta]

You have so much to learn. Stop and start over. Invest in an RO/DI unit. Never use tap water for a salt tank. Definitely look into setting up a QT tank once your tank is completely cycled - meaning it will take anywhere from 6 - 12 weeks before your tank is ready for fish. QT all new fish for 6-8 weeks or more if necessary.

[Scubakid]

lonzoencho, thank you. My salinity gauge (fluval sea type) says 30 on one side and 1.022 on the other, exactly. It is right in the "green zone" marked on the guage. I do not have any other gauges. What other levels should I be testing daily? I figured by getting my water from the more reputable marine aquarium place it would be correct. Perhaps I need to do more at home to make sure.

[Scubakid]

FTDelta. I do have a lot to learn and appreciate the information. I do not use tap water. I use R/O from the same store that has the Salt Water refill station. Only R/O and salt water from there. I sure wish the people at the store would have told me these things as getting the tank started was a lot of time. I do not want to hurt the fish though so I do want to do it RIGHT so they live and thrive. It is not a large tank so I was thinking 2 fish tops anyway. What do I do w/ my wrasse who seems to be doing fine in there now? Can I take the water to be tested and potentially keep it going?

[lonzoencho]

Your salinity is spot-on for keeping marine creatures. The waste levels (Ammonia, Nitirite, Nitrate) and pH are more important in this circumstance. I would ask if your LFS has a cycling agent(nitrifying bacteria) and add some more live rock is feasible. It sounds like your damsel may have had an internal parasite or wasn't quite adjusted to the water quality. If your water test doesn't test well, I would recommend holding off on a water change until your the cycle is complete. FTDelta suggestions are definintely helpful but not critical to the process.

[lonzoencho]

You can keep your wrasse and your system just make sure you test your water and ask your fish to be feed a food of your preference before purchase

[Scubakid]

Thank you lonzoencho. That is very good news. I like the six line wrasse and he seems very healthy. The hermit crabs are doing great too - growing. They have extra shells to move into and a couple of them already have. I will get the cycling agent and add more live rock for sure. I will also read up w/ these book suggestions. Do you agree a weekly 10% water change correct for the 20g tank? Should I be doing this so often?

[Scubakid]

One more quick question. If I hold off on the water change until cycle complete, assuming my fish is okay - just stays in there while it cycles?

[cakemanPA]

The other thing that you will find is that a 6 line in a 20g will most likely be pretty aggressive with any other fish period.

[Scubakid]

cakemanPA can the 6 line be fine w/ no other fish? Do they need other fish to be happy or could I just leave him as the only fish and be okay until I get more experienced and maybe get a larger environmnet?

[lonzoencho]

I would go with a pair of small clowns opposed to the wrasse in your tank.I would give him a couple weeks and see. For the first three months of the cycle I would recommend weekly 20% then biweekly 25% after.

[Mike31154]

Based on the info that the wrasse is doing quite well, it seems like you're on the right track in getting the system started. Water changes are generally beneficial provided you mix the new water well & ensure it's very close if not the same salinity & temperature as the existing water. As far as the Damsel, sometimes you simply lose fish without an apparent cause, it happens. Sounds like you really care about the livestock & the hobby, so keep up the good work and the research. A pair of clowns sounds like a great idea to me as well in a smaller system like yours. They are well suited to a tank this size since they rarely go very far from their host anemone in the wild. Probably means catching & removing the wrasse though.

[Cymonous]

Technically and before anyone should say if you should keep the fish in that tank, you need to get a set of test kits for Ammonia, nitrite, nitrates, and ph. If you have any signs of ammonia and/or nitrites, you should get the fish out. Having any signs of ammonia or nitrites is just hurting the fish and will possibly kill it. If those are fine, then leave the fish in.

When you get more live rock, make sure to keep it wet so you don't have any dieoff and end up with another cycle.

[Scubakid]

Thanks everybody. I am going to get the water tested today and then buy a test kit for on going use. This is important I agree before making any new purchases of anything more for the tank. I think I will leave the wrasse and perhaps trade him in for 2 clowns once I know more about what I am doing and know all the levels are correct. Question for Mike311154, do the clowns need an anemone in there w/ them? I read they don't need one but I want them to be happy and will get one if it is better they have this. Thank you all for your time and helpful responses. Andrew

[Scubakid]

Also, being able to be on the ocean since very little, I have been taught to respect these creatures and the natural beauty of the sea where they live. i wish to do the same with my tank. There's is no substitute for the true natural environment of the reef but sadly we may ONLY be able see these fish in tanks in the future if we don't start caring more for our oceans and reefs all around the world. My Dad was just diving in Maldives and shared a pictures of trash and plastic bottles just floating on the sea. This one pic ruined for me the other awesome pictures he took of the beautiful reefs and sea life there. This really bothers me. I am doing what I can and want to do more when I grow up. I hope others in the RC do the same and I am sure you do. Thanks again

[Salty Dog24]

Six Line Wrasses are known to be agressive. Since you plan on adding more fish in the future, I would not add anything that is shaped like a wrasse, including Fire Fish and Royal Gramma's. In my experience, my 6 line has abused and killed 2 of my Royal Grammas that were added after the Wrasse, and he is picking on my Fire Fish that was in the tank before the Wrasse. He even chases the Chromis around sometimes. Since your tank is a 20 gallon, there is not a lot of real estate in there for fish to declare territory, so your wrasse may be very agressive towards other fish.

[michfish5]

Welcome to the hobby Scubakid! You have already been given some good advice and its great you are looking to learn before you get deeper. So many people don't bother. I would start by reading all the Stickies on here, especially on Tank Setup, Cycling, and Quarantine. And always take what EVERY LFS says with a grain of salt.

Like others said, you will need more live rock. You could probably get away with like 15-20 lbs of it if you need to keep costs down. Try to stack it so there are lots of holes and pass-throughs for the fish to hide it and swim through. Also better for water flow and to prevent "dead spots" where detritus will build up. Do you have any powerheads in there? A skimmer? Are you using an HOB filter or just the live rock? These are things to consider adding if not.

Get yourself an API Marine Test kit. They are cheap and good enough to get you going for a while. Later on you can try other more advanced test kits like Red Sea or Salifert to name a few. But the API will be good enough for now. Don't use test strips! Also you may want to invest in a refractometer to measure your specific gravity instead of a hydrometer. They are more accurate. You already got sound advice about the six line. They can be little buggers when adding new fish, especially more timid ones. And your tank is a little small for it in the long run. When you can, invest in a 10 gallon setup to use for a QT tank. That will be your best investment for adding new fish down the road.

Just read as much as you can and do things VERY slowly. Nothing good happens fast with this hobby. I admire your spirit and commitment. Good luck to you!

[Scubakid]

Thank you michfish5 and Salty Dog24. There is more to think about and learn than I thought - that's for sure. I did go pick up the API marine test kit today so I don't lose another fish and everything looks good levels. I am relieved and think maybe the Damsel was sick or could have been bullied by the wrasse at this point. Not sure what happened but don't plan to add anything but live rock for a while and until I decide what to do. I will get a real QT tank too. The wrasse is still swimming all over and looking great. I like him am not sure I want to part with him if I don't have to. Thanks again!