What A Mess I Made Of My Tank

I was being careless, and now I've got trouble! Last weekend hubby took me to one of the LFS (very good reputation) to get some more Otocinclus. Before Christmas we'd gotten 6, but 2 for some reason died. So now almost a month later we were going to replace them.

Sadly the LFs did not have any. We had a look around, and hubby spotted the black phantomm tetras, and asked if we could add some of those to our 30 gallon, 36" long tank. Ok, so we got 6 black phantom tetras.

On the way home I was planning how I was going to set up the 5 gallon QT, we were also getting ready for guests the day after, and hubby said just plop them in! Stupid, stupid me thought "oh well, it's a good LFS, I put them in a bucket, and do the drip acclimation for 1 1/2 h. I'd done a large water change the day before.

OK, did that, everything was fine, until Monday, when I found one of the new fish dead, on Tuesday another, another on Wednesday, and today I found another plus a dead platy and an otocinclus not doing too well.

Immidiately checked the water: Ammonia 0, Nitrite 0, Nitrate 10, ph 5!!!!!! What the heck? That's a drop from 6.2! Immidiate water change, and thorough gravel vac!

So now I'm left wondering, did the fish bring something in or is my ph to blame?
I've got this beautiful driftwood in there, that has java moss and java fern growing on it! Should I remove it? But I read that driftwood only lowers the ph by a marginal amount! Is it a sign to replace the mechanical filter (sponge)? Should I replace the carbon I'd removed sometime in August I believe? I'm attaching a pic of the tank with the driftwood. It's my first attempt at resizing a picture so I hope it doesn't come out miniscule!

Any suggestions/ideas are greatly appreciated! Thanks!

pH shock will definately kill fish like that! Especially if its new and old fish dying and the new ones looked ok when you bought them!

5 really is very low, whay have you changed recently? Gravel? Stones? The wood?

The only thing new is the cabomba plant! Got it at the same time as the otocinclus in the beginning of December!

I rinse my filter media in old tank water every second w/c. I change about 80% of the water every 8-10 days. I add fertilizer very sparingly, but the plants are doing great!

Tap water's ph is 6.5!

No new gravel, stones, decorations....new conditioner, that makes the water a little cloudy in the first 24 h after the w/c! But could that lower the ph?

Rummynose said:

The only thing new is the cabomba plant! Got it at the same time as the otocinclus in the beginning of December!

I rinse my filter media in old tank water every second w/c. I change about 80% of the water every 8-10 days. I add fertilizer very sparingly, but the plants are doing great!

Tap water's ph is 6.5!

No new gravel, stones, decorations....new conditioner, that makes the water a little cloudy in the first 24 h after the w/c! But could that lower the ph?

Click to expand...

At what point are you testing your tap water? If you test it as soon as you take it from the tap your results will be false, as it contains dissolved gases(Co2 will lower your PH). After 24 hours the water will off gas and the readings will now be correct. Take a glass of tap water and leave it for 24 hours, now test it and you will get accurate readings. If your tap water really does have a true PH of 5, then IMO you need to raise it. Also you need to be keeping fish that thrive in acidic water. Hope that helps.

DevotedToDiscus said:

Rummynose said:

The only thing new is the cabomba plant! Got it at the same time as the otocinclus in the beginning of December!

I rinse my filter media in old tank water every second w/c. I change about 80% of the water every 8-10 days. I add fertilizer very sparingly, but the plants are doing great!

Tap water's ph is 6.5!

No new gravel, stones, decorations....new conditioner, that makes the water a little cloudy in the first 24 h after the w/c! But could that lower the ph?

Click to expand...

At what point are you testing your tap water? If you test it as soon as you take it from the tap your results will be false, as it contains dissolved gases(Co2 will lower your PH). After 24 hours the water will off gas and the readings will now be correct. Take a glass of tap water and leave it for 24 hours, now test it and you will get accurate readings. If your tap water really does have a true PH of 5, then IMO you need to raise it. Also you need to be keeping fish that thrive in acidic water. Hope that helps.

Click to expand...

No, my tap water is 6.5, but it dropped to 5 (or to be more accurate between 5 and 5.5) in my tank!!!

The fish I have are said to be OK in ph between 5.5 - 7.5.

My tank has always been between 6 and 6.5, so the drop combined with the deaths I am now wondering....but I will set out a glass tonight and measure it tomorrow evening, maybe the tap water has a lower ph than before?

Thanks for your help, guys! I felt so lost, it's awful having to fish out dead fish and not knowing how to prevent the others from facing the same! Now I feel I'm not alone in this anymore!

Rummynose said:

DevotedToDiscus said:

Rummynose said:

The only thing new is the cabomba plant! Got it at the same time as the otocinclus in the beginning of December!

I rinse my filter media in old tank water every second w/c. I change about 80% of the water every 8-10 days. I add fertilizer very sparingly, but the plants are doing great!

Tap water's ph is 6.5!

No new gravel, stones, decorations....new conditioner, that makes the water a little cloudy in the first 24 h after the w/c! But could that lower the ph?

Click to expand...

At what point are you testing your tap water? If you test it as soon as you take it from the tap your results will be false, as it contains dissolved gases(Co2 will lower your PH). After 24 hours the water will off gas and the readings will now be correct. Take a glass of tap water and leave it for 24 hours, now test it and you will get accurate readings. If your tap water really does have a true PH of 5, then IMO you need to raise it. Also you need to be keeping fish that thrive in acidic water. Hope that helps.

Click to expand...

No, my tap water is 6.5, but it dropped to 5 (or to be more accurate between 5 and 5.5) in my tank!!!

The fish I have are said to be OK in ph between 5.5 - 7.5.

My tank has always been between 6 and 6.5, so the drop combined with the deaths I am now wondering....but I will set out a glass tonight and measure it tomorrow evening, maybe the tap water has a lower ph than before?

Thanks for your help, guys! I felt so lost, it's awful having to fish out dead fish and not knowing how to prevent the others from facing the same! Now I feel I'm not alone in this anymore!

Click to expand...

Sorry, I wrote that a bit twisted....my brain is very slow today . The pH of your tap water should rise when it has been out of the tap for a while not fall. However, if you have a high level of dissolved Co2 in your tap water then it is possible to cause pH shock to your fish during water changes. During colder weather your tap water often contains more dissolved gases than during the warmer months(just like cold soda holds it's fizz longer than warm soda). If that is the case then you would be best to drive off the gasses before adding it to the tank. To do this you can put it in a bucket and run an air stone in it for an hour.

If however your water pH is dropping that much after you have added it to the tank, then something within your tank is causing it, but a pH drop of 1 is a big shift. I am more inclined to think that it is an issue with your tap water though. Do a test as you take it from the tap then test that same water in the glass tomorrow and see what the difference is. I think that a shift of 1 pH would equate to around 30 ppm of dissolved Co2 in your tap water.

The only other question I have is when did you test your tank water? Was it immediately after you did a water change, or was it a day or so later?

Try to narrow down when the shift is happening.

Thanks a million for your answers and your time! Hmmm, we are having it quite cold here, with temps between -2 Celsius to -25 Celsius.
I will do the before and after test as you suggest....

To answer your question: I tested the tank water before the water change today, because of the deaths. That's when it was between 5 and 5.5!

The time I measured the tap water was in the summer, it was 6.5, and the tank was around 6.2.
So your explanation makes a lot of sense! But I would have to get a lot of buckets to let the water stand for 24 h for my next water changes

Also check your kh, you may have super soft water without any buffering capacity.

thereverendturtle said:

Also check your kh, you may have super soft water without any buffering capacity.

Click to expand...

If I remember right I do have low gh and kh! I used to have those dreaded test sticks where that would show. Would crushed shells help with buffering?

Rummynose said:

thereverendturtle said:

Also check your kh, you may have super soft water without any buffering capacity.

Click to expand...

If I remember right I do have low gh and kh! I used to have those dreaded test sticks where that would show. Would crushed shells help with buffering?

Click to expand...

Yes, a handful or two of crushed coral sand or gravel, will help with the buffering capacity. Maybe if you have room for a small media bag full in your filter, that would keep it hidden from view and buffer slightly better because of the constant flow of water.

thereverendturtle said:

Rummynose said:

thereverendturtle said:

Also check your kh, you may have super soft water without any buffering capacity.

Click to expand...

If I remember right I do have low gh and kh! I used to have those dreaded test sticks where that would show. Would crushed shells help with buffering?

Click to expand...

Yes, a handful or two of crushed coral sand or gravel, will help with the buffering capacity. Maybe if you have room for a small media bag full in your filter, that would keep it hidden from view and buffer slightly better because of the constant flow of water.

Click to expand...

+ 1

thereverendturtle said:

Rummynose said:

thereverendturtle said:

Also check your kh, you may have super soft water without any buffering capacity.

Click to expand...

If I remember right I do have low gh and kh! I used to have those dreaded test sticks where that would show. Would crushed shells help with buffering?

Click to expand...

Yes, a handful or two of crushed coral sand or gravel, will help with the buffering capacity. Maybe if you have room for a small media bag full in your filter, that would keep it hidden from view and buffer slightly better because of the constant flow of water.

Click to expand...

That sounds very doable! Great idea, thanks 'turtle!!!

You are very welcome. It looks like you have an aquaclear filter (my favorite), very easy to add different media to.

Just out of curiosity I tested my tapwater's ph without aging for 24 h, it is a little over 6.5 (not quite yellow with a green tinge) and my tank water is now 10 h after it's 80% water change at 6.

The one otocinclus that was hanging on all afternoon has now died too. My Rummynose Tetras are doing great! Bright red noses, actively swimming, eating normal....

edit: have a test tube with tap water ready to be tested tomorrow!

thereverendturtle said:

You are very welcome. It looks like you have an aquaclear filter (my favorite), very easy to add different media to.

Click to expand...

You've got a good eye, yes it's an aquaclear 50. I absolutely love it, so easy to maintain too!

It does sound like a combination of excess CO2 and low buffering capacity.