portrait of a fish, originally uploaded by olya.

Q: SF wrote,

I have a betta who is about 2 years old. He’s not well. He is quite lethargic, sits at the bottom regularly, has just developed a few white patches and has had popeye in one eye only for about 7 months. I have tried EM, Marycin, MarycinII, Betta Remedy and have just started him on QuICK Cure. I have never mixed medications, have always taken a break between medications. Today, I was at Super Pet and QuICK Cure was reccommended. His severe sluggishness started about 2 weeks ago. I just recently bought a new tank (old one was about 1/2 gal and without a filter). He’s now in a 10 gal. tank, filtered, heated and added the appropriate amts of declorinator and start up bacteria at start up. I bought a test kit today and tested the water (never knew about nitrite, nitrate, amm, ph…etc. until last night doing research online) Anyway, everything was fine but the PH. Ph was well over 8. I have since lowered via ph down pellets and he seems to be doing a little better. Could it have been the ph? BTW – temp is 78. Any suggestions on helping this poor little guy. I would appreciate any advice.

A: I’m sorry to hear about all your Betta’s health issues but am happy to know you have been able to find the information you needed about water parameters on the web. I think the upgrade to a 10-gallon was a great idea and he will benefit from it.

I think that the high pH may have compounded your Betta’s health issues initially but probably didn’t cause them. A half gallon bowl, as you know, is quite small and toxins like ammonia and nitrite can build very quickly. They can become dangerous in just a couple of days. Medicating fish may help but only if the initial cause was fixed, in this case, the bad water. Chances are you were medicating your Betta for the disease but since you didn’t know about the dangers of ammonia and nitrite you weren’t taking the steps to eradicate it. Thus the betta was continually exposed to poor water conditions.

Medications, like antibiotics, are often effective but are also quite potent and can sometimes lead to additional problems. It can be a lot of work for a Betta to metabolize all those medications and repeated exposure could certainly lead to lethargy.

A third factor is your pH. PH above 7.0 (called basic) isn’t ideal for Bettas because they thrive in soft acidic water (around 6.8). Like most of the popular aquarium fish, however, they are very adaptable and can live long healthy lives in higher pH water. One important thing to make note of is that basic water (pH above 7.0) makes toxins like ammonia and nitrite exponentially more dangerous. An ammonia level of .25 ppm at a pH of 6.5 isn’t good but an ammonia level of .25 at a pH of 8.0 can definitely be toxic enough to weaken a Betta’s immune system leaving him vulnerable to a host of common illnesses.

I suspect that your Betta was already being exposed to dangerous levels of ammonia. This coupled with the high pH became very serious for him causing him to continually fall ill.

What I, and most aquarists, don’t recommend is messing with your pH levels. Fluctuating pH levels are far more dangerous to fish then one that is out of the ideal range but still stable. PH down can cause a rapid drop in pH levels, which we call a pH crash. A rapid drop in pH has been known to cause mass casualties and wipe out entire aquariums full of fish. PH is not measured the same way as ammonia or nitrite; it is measured on a logarithmic scale. A logarithmic scale measures ten-fold. Aquarists often forget how important this is when tampering with their pH levels. This means a pH of 6.0 is ten times more acidic then a pH of 7.0 and a pH of 5.0 is then 100 times more acidic then that 7.0 pH level. Once you understand this you realize it is often safer to keep the pH stable even if it is a little outside of the desired range. Once aquarists begin shifting their pH up or down, especially quickly, they tend to experience greater instances of illness or sudden death among their fish. The rule of thumb is keep any pH fluctuations down to less then 0.2 within a 24 hour period to avoid stress induced by rapid or severe fluctuations.

Another problem with pH down is that it can’t work alone. PH is directly affected by KH. KH is carbonate hardness also called buffering capacity. When your water is “well buffered” the KH is adequate and the pH doesn’t fluctuate. In order to change your pH you need to have a low KH. If you have high KH then adding the pH down will only temporarily lower the PH. Soon it will swing right back up again. That rapid drop and swing back up is what kills fish. This is why we tell people to leave their PH alone.

I know that was a lot of information all at once so to recap…

1. Poor water quality due to ammonia was likely the main cause of your betta’s prolonged popeye, fungus and sluggishness.
2. High pH probably made the ammonia even more toxic.
3. Medications didn’t initially work because the poor water quality wasn’t fixed until later.
4. Altering the PH is dangerous and can lead to lethargy or even death.

Here’s the good news. You have upgraded your aquarium so that it will take longer for toxins to build. Once it cycles, the pH may slowly stabilize to a level that isn’t quite so high and helpful nitrifying bacteria will consume the dangerous toxins so they won’t be an issue. Keep the water clean and free of ammonia and nitrite, monitor the pH and KH and soon your betta should be on his way to healing.

The QuICK Cure you are using contains malachite green and formalin and is very effective against external parasites. It has no antibacterial properties and will not treat fungus or popeye. At this time it is probably just an additional stressor. Lately, I have been getting a lot of emails from people getting bad advice from these large chain stores. I think they probably sold you something you didn’t need.

Well, that’s a lot of information to digest so I think I will stop here. You are definitely on the right track now and I think your Betta is going to love his new habitat. Once he’s on the mend you can think about adding tank mates to your new fabulously larger aquarium.


All About Water – Understanding Water Parameters
The Fishless Cycling Method
How PH effects AMMONIA

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  1. Micheal says:

    Hi. My betta fish is lying on its side and it is breathing really hard. This just started happening this morning. It went on it`s betta hammock and is breathing really hard. Sometimes, it gets up and swims really fast with his head pointing up in the air. Please help!

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