Loaches Online Forum

All right, a bit of a neophyte question but I need somewhat referenceable expert opinions:

How long should a new system sit, run or age before introduction of fish, particularly more delicates like rainbows, loaches or SA arowana?

A few notes: will be filled with tap-water of unpredictable chlorination, pond has been puck-chlorinated for probably a decade and we won't be using de-chlorinator (unless you convince me otherwise). After a week of "breathing out the chlorine" I'll start introducing sand, sectioned bamboo, potted sub and emergent plants, "live water" (5 spp of snails, skuds/amphipods, clams, clam-shrimp, cyclops, rotifer, vinegar-worms, Gambusia/guppies etc...) and such to kick-start the eco-system. Is a week enough time to breath? System is long and shallow and exposed to breeze, sunshine and rain.

So, now that the context is set, how long should I run such a system before I put the expensive fish in? Do I need to keep the pump/filter turned on the whole time or can i leave it turned off until the final weeks (electricity is costly and ecosystem is full of tiny beasties) ?
I want to age it as long as I can to get the beasie-counts up, but every extra day is likely going to be a fight.

and yes, I've been working on this project for 2 years now... :)
A

You are dealing with 2 issues here. Removal of chlorine, and developing the nitrogen cycle.

Chlorine can outgas in just a few days in warm weather. A week should be enough time. I would not bother with dechlor, but after the week move on into the fishless cycle. Do not add livestock yet.

Here is the fishless cycle:
Fishless Cycle
You too can boast that "No fish were harmed in the cycling of your new pond"
Cycling a pond means to grow the beneficial bacteria that will help to decompose the fish waste (especially ammonia). These bacteria need ammonia to grow. There are 3 sources of ammonia that work to do this. One is fish. Unfortunately, the process exposes the fish to ammonia , which burns their gills, and nitrite, which makes their blood unable to carry oxygen. This often kills the fish.

Another source is decomposing protein. You could cycle your pond by adding fish food or a dead fish or shellfish. You do not know how much beneficial bacteria you are growing, though.

The best source of ammonia is... Ammonia. In a bottle.

Using fish is a delicate balance of water changes to keep the toxins low (try not to hurt the fish) but keep feeding the bacteria. It can take 4 to 8 weeks to cycle a pond this way, and can cost the lives of several fish. When you are done you have grown a small bacteria population that still needs to be nurtured to increase its population. You cannot, at the end of a fish-in cycle, fully stock your pond.

The fishless/ammonia cycle takes as little as 3 weeks, and can be even faster, grows a BIG bacteria population, and does not harm fish in any way.

Both methods give you plenty of practice using your test kit.

How to cycle a tank the fishless way:

1) Make sure all equipment is working, fill with water that has all the stuff you will need for the fish you intend to keep. Dechlorinator, minerals for GH or KH adjustments, salt, if you are creating a brackish tank...

2) Add some source of the bacteria. Used filter media from a cycled tank is best, gravel or some decorations or a few plants... even some water, though this is the poorest source of the beneficial bacteria.
Bacteria in a bottle can be a source of these bacteria, but make sure you are getting Nitrospiros spp of bacteria. All other ‘bacteria in a bottle’ products have the wrong bacteria.
Tetra Safe Start, Dr. Tim's One and Only and Microbe Lift's Nite Out II all list Nitrospiros bacteria in their ingredients. Using one of these products can shorten the cycle to less than one week.

3) Add ammonia until the test reads 5 ppm. This is the non-sudsing, no-fragrance-added ammonia that is often found in a hardware store, discount stores, and sometimes in a grocery store. The concentration of ammonia may not be the same in all bottles. Try adding 5 drops per 10 gallons, then allowing the filter to circulate for about an hour, then test. If the reading isn't up to 5 ppm, add a few more drops and test again. (Example, if your test reads only 2 ppm, then add another 5 drops) Some ammonia is such a weak dilution you may need to add several ounces to get a reading.

4) Test for ammonia daily, and add enough to keep the reading at 5 ppm.

5) Several days after you start, begin testing for nitrites. When the nitrites show up, reduce the amount of ammonia you add so the test shows 3ppm. (Add only half as much ammonia as you were adding in part 4) Add this reduced amount daily from now until the pond is cycled.

If the nitrites get too high (over 5 ppm), and seem to stay up for several days or a week, not coming down, reduce the amount of ammonia you are adding, or even skip a day. If this does not budge the nitrites, then a partial water change may help. It can happen that the bacteria growth is slowed because of the high nitrites.

6) Continue testing, and adding ammonia daily. The nitrates will likely show up about 2 weeks after you started. Keep monitoring, and watch for 0 ppm ammonia, 0 ppm nitrite and rising nitrates.

7) Once the 0 ppm ammonia and nitrites shows up it may bounce around a little bit for a day or two. Be patient.
You can test the system by adding more than a regular dose of ammonia, and it should be able to handle it.
If you will not be adding fish right away continue to add the ammonia to keep the bacteria fed.

When you are ready to add the fish, do at least one water change, and it may take a couple of them, to reduce the nitrate to safe levels (as low as possible, certainly below 10 ppm)

9) You can plant a pond that is being cycled this way at any point during the process. If you plant early, the plants will be well rooted, and better able to handle the disruption of the water change.
Yes, the plants will use some of the ammonia and the nitrates. They are part of the nitrogen handling system, part of the biofilter, they are working for you. Some plants do not like high ammonia, though. If a certain plant dies, remove it, and only replace it after the cycle is done.

Thanks Diana, that sounds very do-able.
At what point can/should I introduce the invertebrates, and will mosquitos become problematic in the absence of Gambusia (fish)?

I know that generating a good population of the clams and mystery snails will take a while, though the rest of the snails, amphipods and clam-shrimp should explode pretty quickly, particularly if we've got the plants in place.

With outdoors and sunshine I'm also thinking that ammonia will give me green water.... which I can't have, even for a little while.

This thing is about 430 cubic feet, or 4700 US Gal but only 18" deep. 20 guppies will do a number on the mozzie-population without producing too much ammonia, but that'll certainly keep the fish-ed cycling/bacteria production timeline on the high-end. On the other hand, this gives more time for the snails, plants etc.... to get sorted out before the serious fish get in.

Thanks again,
A

That is a good point.
Keeping the livestock out while the ammonia is high enough to grow the nitrifying bacteria does suggest that you will have problems with mosquitoes and green water.
A few suggestions:

1) Mosquitoes grow less in moving water. Add whatever pumps you can to keep the surface moving. (This will also help the chlorine leave faster, then also add more oxygen to help the nitrifying bacteria grow) A flume style of pump seems to circulate the water the best. This is a pump that is centered on the pond. It takes in water from the bottom and shoots it toward the surface. It does not have to splash, or fountain, just create some serious ripples.

2) Shade the pond to keep the sun off to minimize the green water algae.

3) Add one of the products that have the actual nitrifying bacteria so the cycle will go a lot faster. Then you can add the fish right away. These products usually work like this:
Add them to the water a few minutes to an hour or so before adding the fish. Allow them to circulate and the water to clear (they cloud the water for a few minutes). Then, over the course of the first week there may be small blips of ammonia and nitrite, but these usually are not very high, and are very brief. One partial water change is all an aquarium usually needs. But in your pond? Is a 25%-50% water change possible? If not, better to be safe with the fish, and add less.
Perhaps: Add as much of one of these products as you can, then add about 50% to 75% of a fish load based on how much of one of these you have added. For example: If you can get a bottle that is good for 100 fish @ 1" then just add 50-75 Gambusia. OR add all the other livestock- Clams and so on also produce ammonia, and the nitrogen cycle applies to them, too. When you are ready to add more livestock, add another bottle of Nitrospiros bacteria.

Other sources of these bacteria that can make the fishless cycle go faster:
Aquarium filters. LOTS of these bacteria grow on the filter media. If you can take a small amount of filter media from a lot of aquariums you can seed the pond with the proper species of bacteria. Then you can do the fishless cycle to grow more bacteria. This goes a lot faster than starting from nothing.
Live plants. There will be a lot of the proper bacteria on the leaves, stems and roots of plants. Also, the plants themselves will remove a lot of the nitrogen (ammonia, nitrites and nitrates) By adding floating plants to shade the pond (cover about 60% of the surface) algae will not get enough light to grow.

You can grow these bacteria yourself. You need enough water to circulate through some filter media, a pump, and some filter media. For example: A 100 gallon stock watering tank, a 500 gallon per hour pump, and as much sponge, bioballs and other filter media as you can add to the tank. Include the media from the pond filter. Then add lots of ammonia (to 5 ppm) and do the fishless cycle in the stock tank while you are getting the other pond ready. (Of course, if you can jump start the population in here, that will be really helpful, too. Get started right away! It takes time to grow these bacteria. ) When you are ready to stock the pond move all the filter media to the pond, even if you have to let it drift in the pond. Then add the fish and other livestock. Remove the excess media a little bit at a time over several weeks. The beneficial bacteria will start growing on all the other surfaces of the pond, but it takes time.