existing cycle problem

[penguin44]

Hey. I've had an existing betta tank for about a year and a half now with no issues. I did a water test yesterday just before I was going to change the water and noticed odd readings. Nitrates and nitrite at 0.ammo.25 and my ph went from a norm of 7.5 to 6. Non planted except for 2 mossball. What can I do to get this back and what happened? Please help.
Oh also hob filter.

[jlk]

When was the last time you did a water change? How much do you change (%)? How often do you do water changes? Have you changed anything recently (substrate or filter media)? Have you checked the parameters (ammonia, nitrite, nitrate, ph) of your tap water recently? We need a bit more info in order to be able to try & figure out what happened!

[librarygirl]

What size tank? The PH crash might have shocked the bacteria depending upon when it happened. When was the last time you changed water?

[penguin44]

Oh sorry. Ten gallon. Last water change was 3 weeks ago. That's been the norm for a year.. Tap water pH is 7.8 kh I don't know but we have hard water.. Last water was 25% haven't changed media or substrate.

[jlk]

Your lack of sufficient water changes has come back to bite you in the the butt. Your buffers have been depleted & the ph crashed. At a ph of 6, the nitrification process grinds to a halt & ammonia is no longer processed. You also likely have very high nitrates. The answer is a simple one- water changes. Start doing them daily until your tank is fully processing ammonia & nitrite again, your ph is stable & your nitrates are as low as your tap. Once your tank is stabilized, do weekly water changes of 40-50% to maintain a healthy tank.

[penguin44]

Oh I thought it was time to do water changes when my nitrate got up. That's been about once a month. Been fine for over a year. Oh and I stated that my nitrate reading is 0.

[jlk]

Originally Posted by penguin44

Oh I thought it was time to do water changes when my nitrate got up. That's been about once a month. Been fine for over a year. Oh and I stated that my nitrate reading is 0.

Unless your tank is heavily planted or your doing daily big water changes, a cycled tank will have nitrates. It's the end result of the nitrogen cycle. Fish produce ammonia which is converted to nitrite then nitrate. Nitrates are removed with regular water changes. I have to suspect there may be either a testing error or your test is bad. Make sure you really shake & bang the nitrate bottles on hard surface for couple of minutes before testing.

You got away with once a month water changes until now- the lack of water changes has now caught up to you & has resulted in your ph & nitrogen cycle crashing. The buffers in your water are necessary to keep your ph stable. These buffers are utilized as part of the conversion process for ammonia & nitrite. They get used up & need to be regularly replaced with water changes. The buffers, minerals & electrolytes in water are also necessary for fish health. They need to be replenished as well.

Just because what you have been doing seemed to work doesn't mean it was healthy for your fish or your tank. Your tank crashed so this should indicate to you something is wrong with what you have been doing. It's a simple thing to fix- you need to start doing regular water changes to keep your tank & fish healthy. If you have questions, please do not hesitate to ask!

[penguin44]

Ok. How much should I be changing every day?

[eizzle]

The norm would be a 10% water change once a week. More often if your having problems with nitrate or other things.

[jlk]

I would suggest a bit more than 10%. Most of the members on here follow a larger water schedule simply because it keeps your tank & fish healthy. 25% a week would be the bare minimum- with a small tank, I would suggest a bit more (40-50%) simply because small tanks are not as stable as larger tank with lots of water to dilute to toxins & keep the water buffered.

The issue you are going to be facing right now is the build up of toxins (ammonia & nitrite) until your bacteria recover from ph shock. You want to keep these levels below .25ppm while your tank stabilizes. It should stabilize quickly (in a few days) but perform daily water changes until it does. Good luck!