A quick Q about cycling and nitrate

[sunshinehippy]

I wonder if anyone can help.

I have done this before but just wanted to hear from someone who has done this a few times before!

I set up my brand new 55G Malawi tank on Saturday. I added a sponge from the old filter (which has bene running for years in a 125L tank) to the new filter, used tap water (which is very hard), and used Nutrafin Cycle for 3 days just to speed things up. 24 hours after filling the tank I added 2 small platys. I tested the water straight away and the nitrates were 5ppm (this is what they are out of the tap!!). I have tested the water again this morning and ammonia is 0 but nitrates are now 10ppm. Now, I think the nitrates are too high to start adding expensive peacocks - do you think this figure will come down? Why are the nitrates so high so quickly? This did not happen in my other tank when I set it up which had very soft water. Is there a way to get nitrates down out of the tap? I do already have an RO unit but it softens the water and I need it hard for this set up.

Thanks.

 

[bob965]

Nitrates will not come down on their own, they are reduced by doing water changes. It has only been a few days and your only bioload is two tiny fish, I doubt anything at all has happened in your tank yet. From 5ppm to 10ppm nitrate is not a significant difference and can probably be accounted for by variations in your nitrate concentration coming right out of the tap, and slight inconsistencies in your testing procedure.

If it was my tank, I would just take out the platies, and dose the tank with ammonia. Since you're starting with some used filter media, a fishless cycle will go very quickly. You might be waiting a long time if you rely on two small fish to poop out enough ammonia to cycle your tank. And when you're done, your biofilter will only be big enough to support 2 platies anyways.

 

[ward1066]

10 is not high, in fact if you keep it at 20 or less your fish will thrive. I dont even test for nitrates anymore, just do a water change every couple of weeks and it will stay at safe levels, not sure what a dangerous level is. 200,300?

 

[TwistedPenguin]

You might be confusing nitrates with nitrites (with an 'i'). Nitrates should be kept low and 10 is nice and low. Most will agree that over 20 ppm is when you'd want to do a water change. The 'cycle' stuff you added is worthless but you added a mature sponge from another tank-that's what instantly cycled your tank. You should be able to start adding fish. Get a test kit and check for nitrites (with an 'i') just to be sure but I think you're good to go.

 

[sunshinehippy]

Thanks for your replies. No I am not confusing nitrates with nitrites, it is just my other tank has less than 5ppm all the time (maybe I am doing a good job!). I dont actually have a test kit for nitrites - i think I should get one just to be sure. I was thinking along the lines that if I can add the peacocks 2 at a time each week then it would be enough time to slowly build up a decent bacterial colony without causing problems to their health considering I had already used mature media.

Not sure about adding ammonia although I can see the poster's point - thinking that it will speed up the colony but adding fish slowly would hopefully do that?

 

[dawnmarie]

Bob965 makes an excellent point about fishless cycling.
I guess I don't understand the concept of intentionally putting fish in the potentially stressful conditions present in a partially cycled tank.It seems a little cruel, but that's just me.

 

[bob965]

You might be confusing nitrates with nitrites (with an 'i'). Nitrates should be kept low and 10 is nice and low. Most will agree that over 20 ppm is when you'd want to do a water change. The 'cycle' stuff you added is worthless but you added a mature sponge from another tank-that's what instantly cycled your tank. You should be able to start adding fish. Get a test kit and check for nitrites (with an 'i') just to be sure but I think you're good to go.

I don't think he can conclusively call his tank cycled. The results he is seeing don't necessarily mean his tank is cycled, they just mean ammonia hasn't built up high enough to be detected yet. The 5-10ppm nitrate reading is inconclusive. To me, the test tube always looks kinda yellowish like the 10ppm color even when testing pure water.

Practically speaking, it would probably be fine to start adding fish slowly, as long as you pay attention to water chemistry until things stabilize. Testing for NITRITES would be more useful than testing for NITRATES, as this is where problems usually pop up.

 

[mos90]

even if your tank isnt cycled its very easy to add fish and ammonia and nitrite levels at a safe level. daily testing is important and waterchanges may be necessary everyday. prime does a great job of detoxifing ammo and nitrite.

if u are in no hurry to add fish. like bob said. a fishless cycle will take about 2 weeks if done properly. its very easy.

i have 2 30gal breeder tank i just set up for my angels. even though i used cycled water and a cycled sponge filter the tank it still going through a mild cycle. i change 25% water every 2 days, add stabilty every day, add prime every water change. according to my tests nitrites are showing up now, so only a few more days left. the highest i let either ammo or nitrite get are .25 pmm.

i agree that nitate testing at this point isnt important and that nitrate levels under 100 will not cause problems, even though the lower the better.

 

[Toby_H]

There are no “quick questions” about cycling… ‘cause we can complicate the most simple of things
　
You added a sponge from a mature tank as well as a bacteria supplement, right?
　
So that means you have an initial stock of AOB (Ammonia Oxidizing Bacteria) and NOB (Nitrite Oxidizing Bacteria) and also means you likely have some fish waste that was in the sponge. TI think this fish waste in the sponge is where your nitrate increase was coming from… although I also agree that inconsistencies in both testing and reading test results could also be a factor…
　
　
I strongly agree with Bob’s suggestion of doing a fishless cycle on this tank
　
Bacterial colonies will only grow to a size large enough to accommodate the ammonia source, in your case a couple of Platies. But by adding ammonia direct (fishless cycle) you can increase the size of the bacterial colonies at their maximum potential.
　
While I would not ever say that a fishless cycle can be done in two weeks, I would agree that in your situation, when you have seeded the tank with an initial stock of bacteria, you can considerably increase the size of the bacterial colonies in a week or two and it is very likely you could increase them to a suitable size for your intended stock…
　
　

not sure what a dangerous level (of nitrate) is. 200,300?

　
200~300 would be considered “:lethal”, meaning this level will cause death to a healthy fish within 24 hours or so… but much much lower levels will slowly degrade the health of a fish. I often simulate nitrates to cigarette smoke, while moderate levels of smoke are not “lethal”, they will degrade your health and shorten your life span.

 

[mos90]

　
　
　
While I would not ever say that a fishless cycle can be done in two weeks, I would agree that in your situation, when you have seeded the tank with an initial stock of bacteria, you can considerably increase the size of the bacterial colonies in a week or two and it is very likely you could increase them to a suitable size for your intended stock…


may not be common but fishless cycle on my 125g with very little old media took 13 days.