Backyard Aquaponics
A place to discuss aquaponics

I have been running my system for about a week now with goldfish,yabbies and a few plants. Tested and have seen very little happening. Emptied the filter from my turtle tank in the fish tank last night and it looks as though i may have a trace of nitrites now between 0 and 0.25. Does this mean cycling is underway? ammonia has been between 0.5 and 1.0 all week, Ph seemed to spike overnight from stable 6.8 up to 7.2. If i could find startup detailed in the forum i would read it but am having trouble finding anything definitive. Thanks.

Yup, your going exactly right. Keep that ammonia at 1 - 2 and cycling will happen at the maximum speed it can.

Do not let ammonia exceed 4 or 5, or cycling will be retarded.

The basic info and useful info sections of the forum are pretty quick to read through and you should find much of the info you are seeking in there.

As OBO says, sounds like you are doing ok. Patients, cycling with fish usually takes about 6 weeks. Ammonia of .5-1 is enough to get things going. If your nitrites are over 1 ppm, you should probably make sure you have at least 1 ppt (part per thousand) of salt in the system as the chloride ion in salt can help mitigate nitrite toxicity.

Keep the feeding minimal and whenever ammonia or nitrite is over 1 you should probably reduce the feed even more.

As to pH swinging. Diurnal pH shifts are usually due to algae or plants using up the oxygen and giving off carbon dioxide over night and then using up carbon dioxide during the day. In water carbon dioxide is a weak acid and will lower the pH. If plants or algae are causing your pH shift, the pH should be lowest just before dawn and highest at dusk. If it is algae causing your pH shift, I advise blocking as much light out of the fish tank/sump tank as possible. Algae can also use up ammonia before it has a chance to be turned into nitrite and nitrate. But the biggest danger with algae is that it can use up all the dissolved oxygen thereby killing your fish but that is an extreme case.

It might be a good idea to have an air pump with an air stone running in your fish tank if you don't have that already.

Okay, tonight my tests are

Ph 7.4
Nitrates 5
Nitrates 1
Ammonia 1

Does the presence of Nitrates mean i have now cycled and should be throwing more plants in ? Fish are happy and feeding very well, as are the Yabbies. Bean seeds and spring onion seeds are now up. I have also been monitoring tank temp over the last 5 days, since i installed the polycarb roof, tank has almost always been above 20 degrees with a low of 18 and high of 26.9.

I am still contemplating some barra as i can get them for the same price as gold fish anyway. One more question, does anyone know where i can buy Crayfish pellets to feed the Yabbies ?.

Nope... you're cycled when the ammonia AND the nitrites drop to zero...

Your ammonia will drop off first... then your nitrites...

In the mean time... make sure you salt your tank to 1ppt to mitigate against the nitrites...

That's 1kg of seasalt per 1000L....

Sorry, Nitrites are 1. Rup am i salting in anticipation of a nitrite spike ? Or should be doing it regardless?

... nope... you're salting... because you already have a nitrite spike....

Also the term cycled is a bit misleading. It does not imply you can just chuck fish in / do whatever you like.

What you have done is cycled with your current bio load. That is, you have enough nitrifying bacteria to support the bio load in your system.

Increase your bioload and your system will become out of balance. It takes approx 48 hours for the bacteria colony to double in size (assuming correct conditions).

So if you have a handful of goldfish and are 'cycled' you have cycled for that bioload. If you go ahead and chuck in a bunch more fish your ammonia will spike and you'll go through the cycling process again, albeit faster.

I am currently cycling my system on 1L 'humonia' per day. That is a massive bio load, it will also ensure when I add fish to the system I will not have any spikes, infact, my bacteria colony will shrink in size and adapt to the lesser load.

I guess what I'm saying is, just be careful if you decide to up your feed rate / add more fish as you will see spikes - monitor it closely and more importantly, take things slowly.

Sorry should have added relative to my system.

Okay, so wait for nitrites to reach 0 before adding more fish, keep initial feeding of additional fish low to avoid nitrite spike, then adjust fish feeding in accordance with ammonia and nitrite levels?. Do i then increase plant load, or do you guys just plant out when you get nitrate readings that will support extra plants ?

Go ahead and plant.... you do have some excess nitrates... and will have more as your cycling completes...

Additional fish load/feed/waste... will produce more... which the plants will take up in growth...

A perfectly balanced system will probably have readings of 0,0,0... and booming plants...

Agreed, add more plants any time, the small plants don't use too much nitrate when they first start out anyway. The truth is, very few systems are perfectly balanced. Most people have some excess nitrates at least part of the year. Some readable nitrates are not a big deal, it is just when they are really really high that it is not so good. What Rupe is saying, is that in a perfect situation, we might all manage to balance the plants and fish and all so well that we could run 0,0,0 all the time and yet have all the plants doing wonderfully. I've never quite gotten that good myself.

Okay thanks, readings today

PH 7.8
Nitrites 2.0
Nitrates 20
Ammonia 0.5

Will salt with 1ppt later today and put a load more seeds and seedllings in, anything else i need to adjust. Looking at getting some Barra towards end of next week, do i need nitrites at a lower level before introducing them to the system ? Will post photos soon, Beans are growing phenomally, i'm waiting for the Giant to climb down and say g'day.

It is always best for the fish if you don't subject them to high ammonia or nitrites. If you can wait till your nitrites drop to 0 it would be better.

System running 2 weeks now ..... turtle filter junk added a week ago ,, weather warm ,, shouldn't be long to wait now.

Seedlings only really take out Nitrates , they are least harmfull to fish.
Your just waiting on the Ammonia to Nitrite and nitrite to nitrate converting bacteria to grow in numbers.
The spike in Nitrites suggest the Ammonia to nitrite bacteria has grown in numbers ....., the nitrite to nitrate bacteria are a little slower in reproducing.
Can't give an exact date ,, but you are getting very close to cycled.