Should I do water change or just let the cycle continue

  • #1
Hi, I am doing a fish in cycle with 3 redbelly piranhas 4 black skirt tetra & a pleco the biggest being the piranha @ about 4 inches

55 gal tank
What type: tap
Tank cycle began: 1 month ago
type of filtration: marine land canister with 2 sponge filters & a wave maker.
water temperature: 79 F

If fish in cycling

How often do you feed them and how much:eek:nce a day rotate between krill or 1 raw shrimp or 1 silver side
showing signs of distress: they look great & seem happy.
live plants in the tank?: yes
If so are they healthy and actively growing?: I think so (not dying)

Products used while cycling
Prime & stability daily, api quick start, api stress coat & stress zyme. Microbe lift special blend

Testing and cycling process
What do you use to test the water: api master test kit (freshwater)
Did you test your tap water for ammonia, nitrites, nitrates and pH, if so post the results below?: have not tested I just know that it doesn’t have ammonia
water changes: I’ve done 2 water changes one 2 weeks into the cycle & one today
How much: 75% & 50%
Did you vacuum the substrate?: yes but only one area per water change
Did you clean your filter, filter media, decorations and/or glass?: no

*Parameters - Very Important
Tank water

Tap water:
Nitrite: will test in an hour
Nitrate: test in an hour


Everything seems to have been going fine had a ammonia spike & that has gone down then my nitrites spiked & nitrates slowly climbed until now being between 40&80 ppm. Nitrites are still spiked. I was under the impression that once nitrates spike past 40 ppm, I am to do a water change & that should bring my nitrates down to a safe level with 0 ammonia 0 nitrites. Got my spike of nitrates today & did a 50% water change but that changed nothing. Still 0 ammonia & spiked nitrites & nitrates. Should I just continue with the cycle as normal with prime & stability or should I do water changes until nitrates are down… other suggestions?

  • #2
Hi Jacob31991p

Do water changes but don’t deep clean the gravel . The cycle will continue to grow regardless of water changes. The bacteria live ON hard surfaces.
Hold the vacuum just above the gravel and you will be able to pick up enough fish waste ( poop) for now.
Do not disturb the substrate/ gravel at all if possible don’t even touch it. Don’t clean the glass for now either.

40 ppm nitrates is not dangerous to fish.
80 ppm nitrates is not dangerous to fish in the short term.
ANY NITRITES is extremely dangerous to fish.
Depending on the PH any ammonia is harmful even in the short term just like nitrite.

Nitrite and nitrate are bacteria poop not the bacteria themselves. Removing nitrite and nitrate will not slow the growth of bacteria. Changing water will not slow the growth of bacteria as long as you are not changing 50% twice a day there will be more than enough waste in the water to grow more bacteria ON hard surfaces. ON the filter yes but also ON all glass, rocks, ornaments, wires , hoses even the heater is a possible home for bacteria at the moment.

In a month or so that is the time to start cleaning one corner of the substrate per week/ fortnight. In a month you can clean the front panel of glass. Much Later you can clean multiple surfaces without worrying. Much later we still go carefully with the filter . In a few months you can really rinse the filter out hard . Just now be very careful and if positive do not touch the filter unless it’s blocked and the flow is considerably reduced.

You already have a large number of fish in the 55 for a fish in cycle. Change up to 50 % at one time . Any more and you might shock the fish with slightly different parameters. The bacteria don’t care how much water you change.

Let me finish this lengthy reply by saying in an established tank it perfectly safe to change 50% of the water 3 or more times in a day/ weekend.Should you be moving a tank across the room etc.

To answer your question.
Unless you have nitrates in your water supply changing water will lower the nitrate level . However you may have had more nitrate than the test can read. The colour is a bit difficult to distinguish.

  • #3
Get those nitrites down with water changes. Don't let them rise above 0.5ppm. Test daily and do changes as needed to reach that level.

Fish-in cycling is more work and water changes should be frequent and based on your daily testing.
  • #4
Even though we call it a cycle, it is really a food chain. Bacteria consume ammonia leaving nitrites behind as waste. Other bacteria grow to consume the nitrites leaving nitrates behind as waste. You are in the second stage where the nitrite consuming bacteria colony is still growing, and not yet able to consume all of the nitrite being produced. If there were no fish in the tank, this would not be a problem, and would be precisely what you wanted to see happening. Eventually, the nitrate producers will outnumber (or equal) the nitrite producers, and all you will see is the nitrate. At that point your tank will be cycled. Nitrites, however are toxic t fish, even in small concentrations, therefore you have to do water changes to remove some of them. Unfortunately, this may also slow the development of the nitrite consuming bacteria as they will have less to feed on, and their population may will not grow as fast. Still, it must be done, and you must be patient. I never do a fish in cycle, it is too much work. Use a couple of raw shrimp from the supermarket, run your filters, and the cycle will be complete in about 5 weeks. No fish die needlessly from toxins either. Just my humble opinion.
  • Thread Starter
  • #5
Thank you guys.

Similar Aquarium Threads

  • Locked
  • Question


Top Bottom