Water change question...

[Ryosuke]

I think I might've done something wrong when I was doing water change, because one of my two zebra danios died today... (Though, the one that still alive is still very active)

My 10G tank is about 3 weeks old with 2 zebra danios (well, only 1 left now...). Recently, the tank has become cloudy, so I did a 25% water change . Before I changed the water, I have tested the pH of both of the tank water and treated tap water, and they appeared to be the same. However, I found out my test kit was expired later when I tested my water in Petco. The actual pH of my tank was 6.5, while the pH of my tap water was 7.6.

Currently, I have no test kit, and Petco won't have the new test kit in stock until later in the week. However, the water parameters of my tank, about 2 days ago, were: pH = 7.6; NH3 = 0.25 ppm; Water is hard; (if i recall correct from the guy in Petco); Nitrite and Nitrate were no present; Water Temp = 78 - 80 F.

I think the pH difference might have shocked my fish, but beside this, can someone tell me whether I done something else wrong?

Thanks in advance.

[didy]

I don't think anyone will be able to know what else that may have gone wrong, if something did, but that is enough of a ph difference that it may have hurt the fish. Particularly if the fish was going through the cycling period.

[SwimminglyFishy]

Everything sounds fine to me except for the pH. Did you test the temp of the treated water and make sure that it was the same as temp as the tank water? That's the only other problem I can think of...

Do you know why the water in your tank has a lower pH than your tap? Is there something in the water that is reducing the pH? Also, did you age the treated water at all (leave it out overnight in a bucket or container to release any gases)? Often times tap water's pH can change after it has been out of the water system and allowed to release any gases.

I would wait for your new test kit before doing any more water changes. Then, with the new test kit, I would test some aged dechlorinated water and your tank water. If the aged water and your tank water have the same pH, then I would just make sure that you age any water before making water changes. If the two pH values are different then we would have to look into reasons why the tank pH is lower.

[Ryosuke]

I didn't test the temperature of the treated water, but the temperature difference shouldn't be too much. Because the tank water temperature only raised about 1 - 2 F after I added the treated water.

Yes, I did aged my water before the adding to the tank, and the pH value of 7.6 is for the aged and treated water.

I will test my tank water and treated water again once I get the new test kit; and I will update the post if I have any news :)

Thanks

[nickmcmechan]

really need your test results to help you, pH diif should be fine, i would do smaller more frequent water changes with a large pH diff

use a dechlorinator, such as seachem prime, dont 'age' the water

its right to try and make sue the temp goes in the same, do a bit of trial and error, i found that one full kettle into by 14l bucket gives me the right temp for my tanks

finally, you must get a test kit, but imo/ime you have hit either an ammonia or nitrite spike, you need to do 25% water changes twice per day until you can get a test kit and find out where you are....

some questions you can answer right now:

how long was tank set up before introducing fish?
is the tank planted? if so, how much?
was this water change you mentioned your first? did you use a dechlorinator?

PS the cloudiness could have been bacterial bloom which is good - what colour was the cloud?
PPS you need to get a liquid test kit, dont use strips they are unreliable

[Ryosuke]

I use a water conditioner called AquaSafe to treat my tap water; and after I treated the water, I normally leave it outside for at least a day (for replacing evaporated water and my last water change).

As I mentioned in my first post, I used to have a test kit (API freshwater master kit), but it seemed to be expired. So, I need to replace it with a new one; however, the test kit was out of stock in Petco until later in the week. So, it will probably be a few days until I can get a new test kit...

Regarding of the questions you asked:

-The tank was set up for about 3 - 4 days before introducing fish.

-The tank is not planted, there are only decor' and plastic plant inside. Though, I am planning to add plants into the tank in the future.

-Yes, that is the first water change that I have done to my tank.
I did the water change because the tank was a bit cloudy. I have treated my water with AquaSafe and aged it for a day before adding to the tank.

-Before the water change, the water was in white cloudy color. The water was only slightly cloudy, but it became clear after the water change.


Also, if you don't mind, can you explain how you add one kettle into a buckle of water to get the right temperature? Do you boil the water, add to a buckle of water, then treat the water with conditioner? Or do you treat the water first before boiling the water?

[Rbishop]

I do not think your tank is cycled at all....

[ct-death]

Okay, a couple of things:

1st, pH was NOT your issue. If your tap is 7.6 and your tank is 6.5 that's a big swing (I'll get to this in a sec). However, by only performing a 25% water change you are mixing 3/4 water from the tank at 6.5 with 1/4 part water from the tap. The resulting water change would be around 0.25 pH!

2nd, your tank is not Cycled yet. Again, by doing a 25% water change and reading 0.25ppm Ammonia (NH3) you actually had an ammonia concentration of somewhere between 0.3 to 0.4ppm...not safe for fish and was probably the culprit... :(

Getting a test kit is the single greatest thing you can do besides performing partial water changes. Normally the test dictates what is required for water change sizes, however, I would at a minimum do 50% a day. <-Remember, water changes will not adverselt affect your cycling process so there is no reason not do them! Besides, the more you do, the happier your fish ;)

3rd, a very low tank pH vs. your tap is a concern. It can be caused from a number of things, but most likely caused from something in the tank itself. for example, decaying food/waste can raise your pH so this may be a sign that more maintenance is needed. Try not to over feed and do those gravel vacs at each water change

4th, there is no need to 'age' your water using a conditioner such as AquaSafe was it? Besides having buckets of water out is a pain and raising it's temp is an even bigger pain. Simply run you tap and you will learn to match the temp from the tap with your tank.

What's your tank at 78-80 degrees? On my faucet, that's at about 60% cold to 40% hot

Lastly, no more fish until things cycle and you ahve the proper equipment. In the end, it sounds a lot worse than it is.

Enjoy and keep us posted! :D

[rich311k]

Dont worry about the PH. Have you tested your tap water after sitting out 24 hours. I imagine you will find it is much closer to the tank PH than you realize. The CO2 in the water causes the PH to drop. Test the KH in tap and tank I bet they are close to the same, the KH is far more important.

I think the fish loss had nothing to do with the water change it just died from the stress of living in a cycling tank. Keep up your water changes and good luck.

[nickmcmechan]

some excellent advice there!

[Marinemom]

Sounds like the tank is still cycling. Do not add anything else to this tank until the cycle is finished which can take anywhere from 6-8 weeks. After the cycle is complete then you can add more fish but do it slowly so the bio-load has enough time to catch up.

Marinemom

[nickmcmechan]

and get that test kit!

keep up the water changes!

[bkgodfrey]

your tank must have still been cycling. Danios are rather hard to kill. I managed to kill about 3 other species while cycling my first tank but the danios held on. He also simply could have been sick, especially if the other fish appears fine.