Help with water parameters!

[J.Serrano]

So I went on travel for a week and left the tank with an automatic feeder. I came back to find that my water parameters are the following:

Nitrate: 0-20 ppm
Nitrite: 0-0.5 ppm
Total Hardness: 75 ppm
Total Alkalinity: 0-40 ppm
pH: 6.2 or lower (last color in the chart)
Total Ammonia: 0-0.25 ppm
Free (toxic) Ammonia: <0.02 ppm

(I use ranges cause the colors of the test were in the middle of the colors identified on the charts, so its somewhere in there)

The water parameters were normal before, with a little of ammonia, nitrite and nitrates, but neutral pH, and normal readings for everything else.

Things you should know:
1) The automatic feeder is set for two feeding per day. Not a huge amount. Fish eat everything or most of it in less than 2 minutes.
2) I was treating the tank with Pimafix and was on the last treatment. I put it in the tank before I left and left it there for the week, as it said on the bottle.
3) My tank is 7 weeks old. And I believe im in the end of the cycle.
4) I had a bacteria bloom which caused stuff (bacteria) to grow on the glass and tubes in the tank. Water got very cloudy. I scrubbed the inside of the tank which removed the white/grayish growth.
5) Water cloudiness fixed itself over the week I was out.
6) Fish are very happy and healthy and all survived the week.
7) Tank looks very clean. Filter foam looks clean and you cant see any debris on the substrate.
8) House was completely closed and got very hot and heavy. Left a fan blowing air at the tank to help maintain temperature as low as possible. Temperature is set to 72 degrees and I found it at 82 degrees when I came back.
9) Left the tank aeration at the highest setting which was a lot. There was considerable, if not a lot of movement in the surface.


I dont know what is causing this drop in alkalinity and pH. I was told 2 things I could try to fix it:
1) add some aquarium salt. Supposedly it should help increase the alkalinity, which hopefully helps regulate pH.
2) add baking soda to increase the pH.

What can I do to get my water perfect? Why is this happening? Any input from you is greatly appreciated. I find it kinda strange and do not understand it at all. Thanks in advance!

 

[J.Serrano]

Bump. Please help

 

[Fresh2o]

The cycle might be near completion but not quite yet. The drop in pH might have slowed things down. Honestly, you could have skipped feeding them in your absence. The total nitrogen would have dropped and the fish should be fine. The amount of food you give plus the number and type of fish in there could be part of the problem. 2 minutes is more than plenty of time for active feeders to eat IMO. The combination of platies and goldfish make for a high bioload. I prefer to under stock and under feed fish.
Keep up with the water changes. Feed less and possibly think about removing the goldfish.

 

[J.Serrano]

Forgot to update the info about the fish, although i don't think it will make much of a difference.

I currently have:
3 zebra Danios
5 guppies
1 mickey mouse platty
3 red spotted platties
4 baby angel fish
1 goldfish
2 julii corydoras
1 common pleco

I used the AqAdvisor a little while ago and it said my tank was understocked and over-filtered. However, when my fish get bigger i will be very overstocked.

But that raises a question, how does the amount of fish or bio load affect alkalinity and ph? Or does it at all?

I have had the same amount of fish for about 2 weeks now and water parameters were just fine before i went away for a week.

 

[J.Serrano]

I dont know if this has anything to do with the drastically lowered ph and alkalinity, but i live in a second floor on a two level building. The apartment heats up pretty drastically during the hotter days (ive seen temperature get to 85 on its own). Usually when i'm home the windows are open and the airflow is quite a bit which keeps the apartment at nice temperatures (70-74). However, while im gone, the apartment is completely sealed which i guess causes the temperature spike.

Now i wonder... Ive read that warmer air can contain more CO2 and i guess the fish tank will produce a little bit of CO2 on its own. Also read that CO2 can lower pH in water.

My water evaporation over the week was very rapid. Lost about an inch to an inch and a half of water. Good surface agitation.


Could CO2 be the problem, or part of it?

 

[trennamw]

The buffer got used up ... The alkalinity measures your ability to buffer pH, and so when it drops the pH drop follows.

Just be careful about trying to keep water "perfect". PH changes are harder on fish than a consistent "not ideal" pH. It might be that your tanks happy place is 6.5 or 7.5 or something.

But it does sound like maybe you just need a water change, if your tapwater has a decent KH (4 degrees or more KH). Throwing in more baking soda without doing a water change adds total dissolved solids which can create osmotic stress.

 

[J.Serrano]

Buffer got used up? What is the buffer? What does that mean?

 

[trennamw]

I'm not sure I can explain buffer really well ... Buffers help prevent pH from swinging. KH indicates how much buffering capacity you have.

Sort of like Tums, maybe ... It doesn't work as an antacid forever, it gets used up. (No don't put Pepcid in the tank, lol).

So rather than put stuff in to change pH, it's good to start with a good pH and enough KH to keep pH stable.

Crushed coral is one source of buffers. You can also get alkaline and acid buffers, I don't recommend them at all because you just get more swings.

A good starting point is to check the KH of your water. 4 or above is a common recommendation. Putting crushed coral in the filter keeps KH up a bit and is a gentle and stable approach.

Aquarium processes make things more acidic, the buffers help fight back against acidic processes. The same is true on the other end of the pH scale too but we don't see aquariums with rising pH the way we see them with dropping pH.

If your KH is above 4 you probably just need more water changes, because it's the new water itself that brings in enough buffers. A cleaner aquarium is less acidifying from what I understand too.

The main idea though is that 6.5-7.5 is fine as long as it is relatively stable. Doing much more than a water change to adjust pH has its own possibly harmful effects, especially when you're learning. Every time you add more anything to the water it can cause osmotic stress.

It's be good to read up on osmotic stress, pH, and KH before adding stuff to the water.

 

[trennamw]

A few other things ...

Aquariums tend to get acidic over time, always, from all the eating and pooping and stuff.

It's common to see a pH drop toward the end of a cycle, fishin or fishless, from what I've seen.

The higher temp may have helped the cycle a little, but The lower pH may have led to some bacteria going dormant but they didn't die. Your cycle must be doing ok for the ammonia to be that low.

I don't have a ton of experience but I've had to learn a lot about pH and KH and GH as my tapwater is super soft, almost like distilled water. My fish have been healthier since I stopped micromanaging pH so much. Honestly I think the situation you came home to is completely normal and expected and water changes alone will bring it back up. If your KH is low from the tap, consider crushed coral.

Your LFS will test your KH and GH, the 5 in one strips do too. The test tube one is more accurate and I think necessary if you start adding things. But it's easiest to put 5ml in a shot glass and stir with one hand while adding drops with the other ... The test is a pain if you cap and recap the tube and I always lose count of drops.

Our LFS also recommends using a pH test for hydroponics, it measures 4-10 and only goes in increments of .5. It leads to much less freaking out about pH.

 

[Caliban07]

Here is a fantastic article about buffers. I

http://www.mankysanke.co.uk/html/understanding_buffering.html

 

[J.Serrano]

Cool. Thanks guys!

So i did a 40% water change last night. I just tested my water and these are the results.

Nitrate: 10 ppm
Nitrite: seems very much like 0 but the colors in the chart look almost identical so i will say 0.5 ppm
Total Hardness: 75 ppm
Total Chlorine: 0 ppm
Total Alkalinity: around 20 ppm
pH: around 6.5


Fish look happy. Is this really bad water?

 

[J.Serrano]

Forgot to add...

Total Ammonia (NH3/NH4): between 0.25-0.5 ppm
Free Ammonia: <0.02 ppm