please help, Cycling question
 

I am planning to start a 30 gallon tank. I will speed up the cycling process with live plants, some old filter media, and mix in sand from my established tank. I will cycle the tank using two mollies and also some shrimp for algae control.
So, the question: The rule is that you should only add 1-4 fish at a time so that you don't mess up the water chemistry. The fish that will be in this tank are hatchetfish, which absolutely need to be in groups of six or more. SO, since the mollies will return to their own tank once the hatchets are about to go in, will that be ok? hatchetfish have small bio-loads, whereas mollies have big bio-loads. I'd guess that a molly poops 3x as much as a hatchetfish! So, taking out the mollies and shrimp, and adding the 8 hatchets would only change the bioload of the tank by the equivalent of about 3 or 4 fish... right? Sorry if that question was confusing, but would that work, and not destroy my cycle? because I don't want the hatchets to have to suffer the stress of being in small groups for a few weeks.
Thanks a ton for any advice!!!

It worked for me. I traded in 4 adult platys at the same time I picked up 12 Lemon Tetras. I assumed the bigger platys were the same bio load as 6 Tetras so it was like adding 6 Tetras alone. I also have a lot of live plants which is what I counted on to make it possible. No problems. My tank is also well established. Use as many fast growing plants as you can. Test your water daily when you add the hatchets and be ready with the water changes.

Ok, THANKS!
So, I'm also wanting to put 15 tetras and 6-8 kuhlis. They need the comfort of large group company too. So what about when I add them later? I won't have the other fish to switch out. Could I just add six at a time, or is that still too much? Both fish have pretty small bio-loads. I'm planning on it being heavily planted, so will that make it ok for me to add more fish at a time? What are some really fast growing plants?
thanks so much!!!

Often it is mentioned to add all of one species as it is better on the fish. A too small group of shoaling fish are stressed just due to the small numbers. Somehow it creates less of a load to add more of the same than to split them up... as long as you aren't overdoing it.

Certainly if you are replacing some existing fish then you can count that many out of your new fish count.

Actually, it's a 30 gallon. If it is already cycled (I won't get into plants here....suffice it to say they help) you should be fine. I added 12 barbs in a 37 while doing the "silent" cycle. You could easily add six at a time.

As mentioned, just step up your testing for a while to make sure everything is stable.

Jeff.

What's the 'silent cycle' ?

Cross post.... fast stems are dwarf hygrophila (I see 1" per day most of the time... although they have slowed down now for some reason...another topic).

There are a few floaters that are great, duckweed , amazon frogbit (I wish I could get that easily but I'll have to order it I think) and water sprite , they are all in the profiles and I am sure there are more. Anubias are popular and can float or be attached to wood or rocks.

Jeff.

Heavily planted, plants suck up the ammonia so it doesn't ever go through the while ammonia, nitrite spike. Jury is still out on that but it is all in another thread. Silent is a term coined due to not seeing the spikes... I would have called it the invisible cycle but I wasn't there to name it.

I'm working out some details on this idea now. I added a fish a few days after setting the tank up then added 12 barbs a week later. I have a theory about how this works that I am working out now as i don't think it as silent as reported to be.

Jeff.

Are dwarf sag or chain sword fast growing? I would like to include a nice, grassy, lawn/carpet plant.

I don't think so. Substrate rooted plants aren't great ammonia sinks, although they are nice they often take a long time to propagate.

Once you have lots of fast stuff these are great additions for aesthetics though, certainly don't not use them just because they aren't fast growers.

Jeff.

If you're not switching out fish and still want to add a lot of fish you could add , for instance, a number of small goldfish once a week to increase your bacteria colony. Assuming you can return or rehome the goldfish at the time you pickup your new fish, it would be like nothing changed from a cycle standpoint. You have to decide the type and number of fish as well as the length of time they stay in the tank, but the plan is workable. Fast growing plants I like are Wisteria and Anacharis. They're very easy and will do much good for your tank. The more plants you have the better but keep in mind that fast plants multiply fast so you don't have to buy enough to fill your tank , it will fill itself in time.