treating tap water/sick dwarf Gourami


HI all,

As a real beginner I'm more than a little confused with the amount of conflicting advicethere is out there.

I've two questions.

1) When adding tap water during a water change I've bought a chemical to remove the harmful chloramines/chlorine. It says add 1ml to 19 gallons of tap water. As my tank only holds 40 gallons and I'm only doing 10% changes this equates to 0.5ml. The bucket I use to add the water only holds 2 gallons. What is the correct way to treat this tap water?

2) After allowing my tank to cycle for two weeks I added a few fish. Three dwarf gouramis and two mollies. One of my gourami's died with what looked like a hole in his side. A second has now developed a red raised mark down one side from top to bottom and is taking to hiding away. I've carried out regular water changes in the four weeks the tank has been working. PH is 7, Ammonia 0, nitrites 0.25 and nitrates 10.

Any assistance would be welcome.




ok, your readings look good, nothing to wory about there, a for the water conditioner, just follow the directions on the bottle, if you're doing 10% water changes, you'e only changing 4 gallons of water, most people do 20-25% every week.

as for the dwarf gouramis, were 2 of them male?, if they were, they will fight each other, similar to a betta, but not as aggressive, the lfs I go to will only sell them in pairs, and you get a male and a female for that reason


Your readings need some attention....

First off, have you let your tank go through the complete nitrogen cycle? Did you take readings through the cycle period and prior to adding fish? I found that this is the best way to truly be sure your tank has fully cycled. If the tank hasn't completely cycled this will be a problem...I see that you have zero ammonia, but show .25 nitrites...Nitrites are more toxic to fish than ammonia and though it is only at a .25 reading it is not good for the fish. It will harm their immune system and make them more succeptible to disease. It is important to get this number to zero as quickly as possible. Do this through water changes. I would change 20-25% and take readings the following day. Keep monitoring for about a week to make sure that the readings are stable and perform water changes as needed to get that number down to zero. Your optimum readings should be: pH: 6.8-7.0, Ammonia: 0, Nitrites: 0, Nitrates: <20.

Treat each bucket of water you add back to the tank if using a small bucket. If you aren't already doing so, you may want to add live plants to the landscape. They will help with chemical breakdown and also can help stabilize your pH.

As for the dwarf gouramis - always: Buy in pairs (one male, one female) or solo....Even in pairs some will fight. Provide high cover for them as they are top dwellers. Floating plants or plants that grow tall will work well. Place a couple at opposite ends of the tank so that if they do spat they will each have their own place to go for cover. I keep only one male Neon Blue Dwarf GouramI and he think's he's king....Chases the swordtails around the tank.

If they have scale and/or fin damage you will want to treat them....I have never had this problem before so I am unsure as to what to recommend. Check with your lfs and they should be able to recommend the proper medication. Be sure to follow the directions properly.

Good luck!
  • Thread Starter


Many thanks for the advice. I now only have one dwarf gouramI - the other died last night.

I'll keep doing the water changes until I get the nitrites down to zero. I've realised like most new beginners I've possibly added fish too soon and without the nitrogen cycle been completed.

Here's hoping regular water changes will solve the problem before any more fish die.

I'll keep you posted.
  • Thread Starter


One of my mollies has now died with the same red patch down its side. My water tests now show nitrites 0 Ammonia 0, I think although it could be .1, nitrates 10 but my PH is coming out as 6.2?

Following a water change this goes up to 7.0 but after a couple of days goes back down to 6.2. I have a number of plants in the tank and they look healthy enough.

Why is it doing this? Has my tank cycled? Why are my fish dying?



When your tank readings are consistently ammonia 0, Nitrites 0 and Nitrates 20 or less then your tank is cycled. Your ph is fine.
Red marks sound like ammonia burns, but if no ammonia maybe an injury, how about the decor in the tank, any sharp edges?
Monitor your water closely as fish deaths can cause your ammonia to spike.

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