Film On The Top Of The Water, Ph Dropping

[idlefingers]

I've just done the first water change on my week-old 30g convict species tank (used a mature filter) and noticed that there's a wierd oily film (?) on the top of the water..

And the water smells fishy.. Like the smell you get on your hands after handling a fish. I'm not sure what a tank should smell like, but my 50g smells kind-of 'earthy', so this one smelling so differently surprised me.

I've been testing the water throughout the week and ammonia, nitrite and nitrate have all stayed at 0, 0 and 10. One thing I have been noticing it the ph slowly dropping. Started at 6.8, then 6.6 by mid-week and now 6.4. Which I'm starting to worry about now.

I think the PH dropping is due to the rocks. I can't remember what type they are, but I'll ring the shop tomorrow and find out.. They told me they wouldn't alter the chemistry whatsoever..

So, do how can I get rid of the film on the top of the water? Do I need to worry about the smell? And what should I do about my PH dropping?

 

[helterskelter]

Do u have any filtration or aeration on the tank?

 

[idlefingers]

I've got an Eheim Ecco 2234 with the outlet breaking the surface to get extra airation

 

[helterskelter]

well the only time i see oil like surface when their is filtration breaking the surface is when a fish has died and decomposed or a cleaning product has been used near the tank and that's about it, is either of them possible?

 

[idlefingers]

There's no dead fish and nope, haven't used and cleaning products around it. I did paint the back of the tank the other day, but I sealed the tank with cling-film to make sure nothing got into the water. Also the film was there before I painted the back.

The fish seem completely happy..

 

[PRW1988]

The smell is more than likly ammonia... Dispite the fact that your readings are telling you theres no ammonia, chances are there is... As for the PH drop, you could always just get a PH buffer which will help to maintain your PH at whatever buffer level you got (usually it should be about 7.2PH), the film on the water, not too sure about, did you wash the rocks with soap? Because there may have been some left over residue from the soap on them which has now entered and contaminated the water...

 

[Tolak]

It also could be from what you are feeding. Higher protein foods tend to do this.

 

[idlefingers]

I haven't used soap on the rocks.. just rinsed them with hot water and brushed them a little.

The filter was previously running on a tank with a much higher stocking and was dealing with much more waste and so I'd be surprised if it's having problems dealing with this, much, much smaller stocking. I thought the ammonia tests were quite trust-worthy? Im using the API liquid tests. I might take a sample of water to the lfs and see if their tests pick anything up.

It also could be from what you are feeding. Higher protein foods tend to do this.

Beefheart is high proetein, isn't it? I've been feeding that (as a treat), so that would make sense if so. If that's the case, is it anything to worry about? Is there a way to get rid of it?

 

[PRW1988]

good idea gettin the LFS to test the water, the other thing is, the brush that you used, had it been used before? If so chances are it had a residue of some kind remaining on it so that may be in the tank contaminating it, or like Tolak said it may be a high protein food, what's the stocking on the tank? and what kind of food are you feeding?

 

[Tolak]

Beefheart is a high protein food, but an excellent conditioner for breeders. It will cause this, try increasing water changes, as well as bio filtration.

 

[idlefingers]

good idea gettin the LFS to test the water, the other thing is, the brush that you used, had it been used before? If so chances are it had a residue of some kind remaining on it so that may be in the tank contaminating it, or like Tolak said it may be a high protein food, what's the stocking on the tank? and what kind of food are you feeding?

The brush is a nail brush only used for cleaning tank stuff and never touched soap. Who knows what it went through at the factory but I rinsed it thoroughly before using it. Perhaps it has something on it. But then again, I've used it many times before and never noticed a film on the water after adding something.

It's got 2 x 1.5" Convicts and a load of rock makiing caves and that's it. I'm going through my community tank food and seeing what they like, so I havent got a particular food or set of food which I feed them at the mo. But, in the last week, they've tried Terta Prima, TetraMin Crisps, TetraPro Veggie Crisps and Beefheart. They've loved it all. Better fed than I am.

Beefheart is a high protein food, but an excellent conditioner for breeders. It will cause this, try increasing water changes, as well as bio filtration.

Thanks tolak! I'll do that!

 

[PRW1988]

How often have you been feeding the beefheart to them? (not sure if you know) but it should be fed very sparingly because it can lead to fatty liver disease, which may lead to the death of your fish... I personally only feed any of my fish beefheart once every month or 2...

 

[idlefingers]

How often have you been feeding the beefheart to them? (not sure if you know) but it should be fed very sparingly because it can lead to fatty liver disease, which may lead to the death of your fish... I personally only feed any of my fish beefheart once every month or 2...

Oh, okay, I didn't realize that. I've done it twice in the week I had them. I'll cut that down drastically now. Thanks. Would bloodworm be a better treat to be used once or twice a week?

 

[PRW1988]

Yes, much better... Bloodworms and brineshrimp are IMO the best treats... and beefheart is good to feed sparingly...

 

[Tolak]

Beefheart will lead to internal problems if overfed, especially beefheart purchased from your lfs. It is poorly prepared, with plenty of fat & such left in it. You are better off preparing your own beefheart, there are plenty of recipes online. Adding things such as spirlina, spinach, various seafood products, along with vitamins will help prevent problems, as well as giving your fish a more balanced diet.