Help please


New Member
Hi, please bare with me- we are new to this!
My son and I have set up a marine tank. Cycled it, all going well. Water tested ok, so put a hermit crab in. He went well, a couple of weeks later we had water tested again. They told us it was perfect. We bought 2 clown fish and a bubble tip anemone (since found out it is not recommended to get anemone this early, but it was advised it would be fine and it seemed to be). All going really well for 6 weeks or so. Started to get different algae’s. So went to the fish shop and purchased a lawnmower blenny and 2 x purple Chromis’s. Water all tested perfectly still. My son dosed tank with Melafix a couple of times, just in case. Fish all getting along great! Lawnmower cleaning up algae nicely. 2 days later 1st chromis died, then 2 days later 2nd one did, 1 day later lawnmower dead. Clown fish stopped eating and anemone moved a couple of times and now not opening properly. Got water tested and still perfect they said. Clown fish acting very strangely. Still not eating and seem obsessed with a small cave in the tank. Seemed like they may have been nesting and we wondered if the girl had laid eggs in the cave as the male was staying at the front of it and the female not going far at all. Still not eating. We thought maybe they got territorial and killed the other fish, although they seemed to all get along great. Today, only 2 days after lawnmower died, the male clownfish was found dead. Female still won’t leave the front of the cave and the anemone is looking very sunken in and hermit crab hasn’t moved for a couple of days. We don’t know what to do! Water tests are perfect. We just don’t know where we have gone wrong or what to do from here! We have googled and googled and can’t find anything. It definitely doesn’t look like there is any disease, but we are still learning and finding it hard to get advise! Thanks very much!!


Well-Known Member
This is sure going to sound like I'm ripping on you. I don't intend this. However there are several things your doing wrong, and there are a few questions that need to be answered.

First get your own test kitd and do your own water testing. Don't depend on your LFS to do decent water testing. I have posted this before but it's worth repeating -
DaveK's Standard Lecture #4 – Test Kits

There are a host of items that you may wish to test for in a reef system.

First before you worry about the other tests, make sure your SG is correct. I highly recommend using a refractometer for this measurement. Aquarium grade hydrometers tend to be very inaccurate, especially when used over time.

Once you have the SG correct you'll need the following test kits for the initial cycle -
pH (This can also be done via a pH meter, which is more accurate, and expensive)
Nitrate (low range)

To properly monitor the water, especially for corals, these these kits are often used -
KH or Alkalinity

There are a host of other test kits you can get. I have some of them but do not typically use them.
Iodine - only needed if you are dousing iodine, which is not something I recommend.
Copper - only needed if you are treating a disease in a QT tank with copper.
Silicate - only needed if you suspect a problem with silicate in the water.
Strontium - only needed if dousing strontium

I think I've covered most of the major ones.

Each test kit works differently, so you need to consult the manufacturers instructions for each test.

As for brands, in aquarium grade test kits I like Elos, SeaChem and Salifret. Hach and LaMotte test kits are excellent, but extremely expensive. Most of the others are ok. Like anything else you get what you pay for.

If you do get a reading that seems way off, repeat the test, and if it still seems way off, use another brand test kit and repeat the test. In other words, consider that the test kit may be wrong.

You'll notice that you most likely will need to get a lot of test kits. It's often a lot less expensive to order them via the net, and you'll also know the test kit hasn't been sitting on the LFS shelf for years.

End of the test kit information.

Next, the tank was treated with Melafix. Never ever medicate a display tank to treat a fish disease. Always remove the fish to a quarantine/treatment tank and treat there. Using a med on the display tank likely killed off all the beneficial bacteria you want in a reef system.

It is also very likely that your tank was not cycled properly. With the adding of the fish and then medicating the tank, you likely had an ammonia spike and this killed most of the fish.

As for what you should do now. If at all possible, return the anemone to your LFS, or give it away to someone that has an established tank and can maintain it.

Next, you need to get the medication out. This is going to require 4 to 5 partial water changes of about 50%, doing each one several days apart. Match the tamp and salinity carefully. Carefully monitor ammonia, nitrite, and nitrate during this time. They can spike, causing problems with the livestock you have left. While this is going on feed the remaining fish and other livestock very lightly.

Next, you going to need to get the tank fully cycled. Once the water changes are complete, add a modest amount of live rock and live sand. You don't need much, your only using thins to seed the tank with new bacteria. You can also add one of the bacteria starter additives, such as BIO-spira or similar product. Note that while a lot of these say the tank is cycled in 24 hours, I recommend you wait a couple of weeks or more before trying to add anything else.

Tell us more about your system. There may be other areas then need attention.
How large is the tank?
What kind of filtration and/or skimming system do you have on it?
What kind of lighting are you using?
How mych live rock and live sand do you have in the system?
What are your exact water parameter readings? Note that a statement like "all parameters are fine" doesn't convey any information at all. We don't know what was tested or the resulting readings. What might see ok to you might indicate a serious issue to someone else.

I hope all this helps a bit, and we can get your system turned around.