Water Reading Questions ???

Cribbinator

Cribbinator

Fish are Friends, Not Food
May 26, 2004
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Alpharetta, GA
www.thecribbs.com
Hello,

I have a question regarding water readings after a "fishless" cycling process. My nitrites and ammonia have been at 0 for 2 days now and before I add the fish I wanted to take a nitrate reading. I did it and the reading was at 80ppm. I went ahead and did a 20% water change waited about 15 min for the water to cycle through everything and then checked it again. The reading came out at 70ppm after doing a 20% water change. My questions are:

1.) What else can I do to get it down to a safe level to add fish ?

2.) What level of nitrates would it be ok to add fish ?

3.) Once the fish are added how often can I do partial water changes since it is still in an "after-cycle" state ?

Any quick help or info would be appreciated, I don't want to leave the cycle complete tank empty for too long and damage the cycle process at all.

Thanks,

James
 
Shoot for under 40ppm, unless you have really special fish.

Plants love Nitrates. If you can have some, add them.

Algae loves nitrates too... so if you can't add plants, keep your lighting down, or change a lot of water out.

From here on out, I would only change water as part of a "normal" water change schedule (which will depend on what you put in the tank)- OR, if your tests show dangerous levels of ammonia or nitrites again.

Add fish that might work with what your "ultimate" goal population is. Maybe avoid bottom fish for a while, until you are sure you won't have ammonia spikes.
 
10ppm to 20ppm

The perfectionistic fish keepers I know try to keep nitrates below 20 ppm. Some people think 40 ppm is OK as a maximum. It may depend on the fish also.

That means that now you would do an 80% water change to go from 70ppm to about 14 ppm nitrates. Then every few days you'd test the water and when it got to 20 ppm you'd do another water change to bring it down.

Eventually you'd work out the maximum level and the timing and volume of water that it took to make that work for you. Maybe 50% every 2 weeks, or 20% every 3 days, or somewhere in between.
 
Have you tested the NO3 levels in your tap/ source water? It's possible you have high levels to begin with, my tap water has 40ppm on a good day.

I have to do 50% water changes bi-weekly in my planted tank just to keep it below 70ppm. Even though I should probably try harder to lower it, I've never seen any visible effects of having the level consistantly that high. I agree with anonapersona in that you will eventually find a schedule that will give the results you want or settle for.
 
So with those levels is it OK to add a small set of fish now ? I was thinking of doing a more drastic water change before I get fish but I would probably have to do a 50% water change but I'm thinking that would be bad right after just finishing a "fishless" cycling process ... am I right ?

Thanks,

James
 
theoretically, a large water change would have little or no effect on your tanks ability to process ammonia (i.e. fish waste). The goal of cycling a tank is to build up colonies of bacteria in the filter medium, not the water itself.

i would go ahead and do the 50% change and retest. those tests can be hard to read, particularly the color coded ones produced by, say, Aquarium Pharmacuticals. the difference in 30 ppm can be so subtle as to take a master painter.

out of curiousity, do you use a dechlorinator? many municipal city water systems use chloramine compounds instead of chlorine compounds... chloromines are ammonia ions bound to the chlorine ions do decrease their evaporative properties.(in simple terms)

it might be possible that you are introducing added ammonia to your tank in that manner, which would in turn increase your nitrate readings. Many dechlorinators also neutralize ammonia/ammonium as well. if you are using a product that doesn't, that may be your answer. if you visit the EPA website, you can obtain water test results for your area. (epa.gov, i think... you click on a state if i remember right... i used to have the link, but it died with my last comp)

in general, i'd say go ahead and add a few fish, but stay away from the expensive ones at first.

good luck

(if my science is off in any of these statements, feel free to correct me)

:dance:

btw, this is my first post... so far i like the site,

eric
 
Indi is right- excepting that the bacteria (nitrosomonas and nitrobacter) can and do colonate in the substrate as well (just in lower numbers).

Keep in mind a little known fact- pH below 7.0 will have ammonium, not ammonia, which occurs above 7.0. This is important as ammonium is far less (some even say NON) toxic. So test your pH. I am going to bet you are above 7.0 though.

The other thing I wanted to add though is this. You have cycled with a less than natural approach. I know a lot of people do so, so it is not the approach I would criticise. What the difference is between that approach and the one using fish is, with fish, providing you have a stable number of fish, once the cycle is complete, you can assume that the bacteria colony is up to speed with the waste amount that those particular fish will create either due to their size, or number. So, for example, one can say after cycling "I had 4 mollys in the 35 gallon while cycling. It has leveled out. I now know I can add say, 2-3 more Molly's at a time and the bateria colony growth will keep up (will grow accordingly).

With the fishless cycle, you have no relative reference point to rely on. So how many fish did the ammonia driven fishless cycle represent? Now that it has cycled, will it handle 5 Pristella's? Or does it need 15 because the cycle has driven the bacteria that high?" So, really, you are going to have to pretty much guess how many fish it needs or can handle.

I just flat out prefer cycling with fish, plants, and some media from an established healthy tanks filter. You can cycle just about any size tank in a week (or two, tops) with that method. Of course that can be hard for the person who is new to this, and has no other tanks to rely on...
 
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picky, picky, hehe, just kidding... i was refering only to bacterial populations existent in the water column only, not all surfaces, but good point. you keep people on their toes, tetraB. I like that.

another good point is about your intended bioload. if we are discussing a fishless cycle heavy on the ammonia, as indicated by the high nitrate levels, you might see a die off of bacteria if the added fish do not replicate or slightly exceed the bioload (fishwaste) produced by the added fish.

In any case, when you add your fish pay particular attention for nitrate poisoning, most easily recognized my redness around the operculum (gills). if the nitrates are indeed at a lethal level, the symtoms of nitrate poisoning should appear within the first day or so, if not hours.

on average, bacteria reproduce every twenty minutes, so there is some margin for error. if the first additions survive in top form, keep em comin. you dont want to lose those bacteria you worked so hard to grow

(had to add the names, huh.. :cool: )
 
One other thing, and I can't recall if Indi brought it up or who did... but yes, muni water can have nitrates (as well as phosphates). One thing oft overlooked is well water... farmland area well water can be high in both nitrates AND phosphates... so can muni water that comes off of either reservoirs or aquifers that are near heavily farmed areas.

I have had very VERY high nitrates in a tank, and even very sensitive fish lived in it. The key to many of these things being out of whack, and whether or not fish will survive in them when they are so far out of whack, is often simply: were the fish in there over the time period while things went out of whack, or were they introduced (shocked) to the out of whack compounds due to being transferred from one tank to another. You could have Neons living in say, 80-100ppm Nitrates, and put some other neons in from a tank where they have been living in 20-30ppm, and you might lose a few over time, while those who have been living in it are happy as can be...
 
Thanks for the replies. I'll have to test my city water and see what the nitrate levels are before I even put it in the tank. Yes I am using a dechlorinator (SeaChem Prime). I'll go ahead and do a 50% water change today and see if the numbers will go down. I'm assuming this is ok since most of the bacteria is not in the water but in the gravel and filter media ? Aslo yes it is hard to read the exact color because once you get over 50ppm it only varies by certain shades. Hopefully I am alittle off in my color reading and it is lighter than I think it is.

Thanks again for all of the replies.

James
 
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