Plan For Starting A New 30 Gallon Tank Using Mature Media From My 75..

[ctsv510]

I had a 30 gallon long tank, fluval heater, and a Marineland Emperor 400 just collecting dust so I pretended to have nothing better to do with my time than build a DIY stand for the tank and move some fish from my 75 gallon over to it. I built the stand and set everything up and proceeded with moving mature media from my fully cycled 75 gallon tank. The 75 gallon has two filters: an emperor 400 with 3 filter pads, one media container filled with bio-ceramic media, and of course the two bio-wheels, and a penguin 350 with two filter pads and a single bio-wheel.

I took two of the filter pads (been in the tank for months) from the 75 and put them in the filter on the 30 and then replaced the spots in the 75 with new filter pads. I ran the new tank for a few hours and then moved a single gold gourami (only about 3 inches) into it. My thought is that these two mature filter pads should already house enough bacteria to take care of the small bio-load from the gourami.

I haven't tested levels yet because I figured it's too early (did this all tonight), but my question is should I expect this new tank to pretty much be cycled and safe for the fish at this point? I will be testing the levels starting tomorrow (I did feed the gourami tonight with a few flakes), but I thought I'd throw the scenario out there and let you experts chime in.

The ultimate goal is to move 5 odessa barbs and a single male swordtail (my son had to have it) to the new tank and throw in a couple rubbernose plecos and one "cool" fish, most likely a Jewel Cichlid. The research I've done says this should work, and worse case scenario the jewel comes out of the 30 and goes into the more aggressive 75 gallon. I wanted to move 4 giant danios out of the 75 to the 30 but I changed my mind based on their size and swimming activity - they're 4 inches long and quite fast, and even in the 3 ft 30 gallon tank I don't think it's enough room.

So...what are the thoughts on this "cycle" or lack thereof? And no need to harrass me about throwing a cichlid in with these other fish....my other tank is a mixed community of semi-agressive tropical fish and carefully selected cichlids and they live in perfect harmony in neutral water conditions.

 

[Miles_hot]

personally I would not have moved the fish - not due to any behaviour etc concerns (I'm not experienced enough to comment!) but on pure ease grounds.

I would suggest that you use ammonia and bring the 30G tank to 5ppm and see how fast it processes it all. Not knowing the filters you refer to I have to ask the seemingly daft question - how much of the total bio filtration media in the 75 tank does 2 sponges represent? If more than 1/3 I would be doing some pretty careful testing of the existing tank just to check for spikes etc.

Assuming that 2 sponges is not 40% of the total bio media the 30 tank is probably not fully cycled (though it should easily handle one fish! ).

My concerns about moving a single fish into the new tank is that there will not be enough load on the sponges and some of the precious bacteria will die back, you will then have to very slowly build up the stocks If you were to do a seeded fishless cycle (which I suspect will be fast) you can get more fish in at once (say 75% of full load).

Just my thoughts

Miles

 

[fluttermoth]

I just want to warn you about jewel cichlids; every one I've ever known has ended up being kept on it's own; they are the most vicious fish I've ever had the misfortune to come across! Lovely as a single fish in a tank, but utter carnage if you try and put anything else in there...

 

[ctsv510]

Concerns heard....tested the water this morning and ammonia is at 0.50 ppm. I removed the gourami and put him back in his old home in the 75 gallon - I tested the water in that tank to make sure I didn't effect the bio filter and the ammonia and nitrite are still at 0.00.

Based on what I have read from others I was under the impression that mature media is almost an immediate cycle but based on your responses I realize I did not consider % of the bio filter that I transferred to the new tank. I didn't want to drastically effect my already cycled main tank so I only pulled two filter pads, but based on a rough estimate this was probably no more than 15% of the bio filter based on surface area, and that is a rough estimate. I probably didn't take enough bacteria to the new tank to have it be already cycled, and after my fish-in cycle I did on my first tank a while back, I swore I wouldn't do a fish-in cycyle again.

I'm not comfortable with any fish in the new tank yet and going to fishless cycle it until it's converting 4ppm of ammonia over 12 hours as recommended. I'll grab some ammonia from the store on the way home today and proceed with dosing that in the new tank until it's fully cycyled. Then I can move all the fish at once (if I can catch them) and be comfortable that they are safe.

Regarding the Jewel Cichlid - I will consider your thoughts before I purchase one. Any recommendations for a single fish for this 30 gallons would be appreciated...

Since I haven't stocked this tank yet, I'd also be open to hear any recommendations for full stocking of the 30 gallon tank that doesn't included shoals of small fish. I can be very fickle when it comes to these decisions so plans are ever set in stone.