Complicated cycling question

[luvreefs23]

Ok, try to follow me here...hope i can word it right. I recently tore down a 150 gallon and replaced with a 215. I saved about 75 lbs or so of the live rock by keeping it in a brute garbage can with a heater and pump for a week. I let about 50-60lbs of the rock dry out cause it was just plain nasty. The nitrates in the 150 where sky high, off the chart on a salifert test kit. Anyway when i set up the new tank i used all the rock from the 150 (dried up and kept in old saltwater) and used 140lbs of new live sand. Filled the tank up with 50 gallons or so of the old water in that was in the 150 and made up the remainder needed. My salinity fluctuated by a couple points here and there thru out the week as ive been adjusting it. I have done a few water tests as i am trying to add fish and some coral this weekend (tanks been going for 2 weeks now). Nitrites read 0, ammonia read 0 and nitrates around 0.25. My question is did i avoid the cycle by using live sand and saving old rock or am i merely reading the nitrates i dumped back into the tank using the old rock and water and i will start a cycle again? Im hoping im reading the end result of a cycle, im using chemipure and carbon and running my skimmer 24/7 ( a warner marine as200). I just wanna get some opinions to make sure coral and fish will be ok this weekend. Also i know my nitrates are a little high for coral but im planning on another 40 gallon waterchange before i add livestock.

Thanks in advance

Dennis

[luvreefs23]

oh also, water is crystal clear and ive seen some trails of worms burrowing into the fresh sand on the side of the glass near some of the rock

[redfishsc]

Do not put any coral in that tank until you are dead certain the cycle is done. I personally would wait a week or two AFTER adding some fish just to be cautious and certain that you are showing no nitrite/ammonia.



As far as "did I avoid a cycle" the answer is "probably". I set up a 10g nano with about 15 pounds of LR from a very healthy tank, and 3 gallons of water from that same tank. I never once saw ammonia/nitrite. Not once, and that was nearly two months ago (and the tank is full of happy coral now).

How long has it been since the new tank was set up with water?

Personally I would test the parameters for a week to see if there is any ammonia/nitrite/excess nitrate from the rock that you dried out, it may have a TON of organics that are just about to begin rotting and send your nitrogen readings up to the clouds. Maybe.

If after a week all the numbers look good, add a few fish and feed them enough to feed the bacteria in the tank, and check nitrogen params every couple of days.


I just err on the side of caution with this sort of situation. I've seen corals survive an all-out ammonia bomb (from folks killing cyano with antibiotics, thus killing the nitrifying bacteria, though that doesn't always happen). But I wouldn't put any coral or any sensitive fish in the tank until MINIMUM a week or two of stable numbers with fish present.

[luvreefs23]

even with a 140lbs of live sand added to? tanks been going with water since november 23rd, tested this past sunday and only nitrate registered at 0.25

[redfishsc]

I don't have a lot of experience with live sand, and I've heard a lot of folks say it's a waste of money if are starting with well-seeded live rock. Your sand bed isn't going to be doing the bulk of the nitrogen cycling because it pales in comparison to the amount of water flow and oxygen that's available to the surface of the live rock. The sand just doesn't have much water flow through it.

I personally just use dry aragonite simply b/c it's cheaper, although I will certainly use sand from an established tank if it's available (has lots of worms and pods in it). Most live sand seems to me to be sand with bacteria, not higher organisms. In other words, the same stuff that the rock comes with.



Now, as far as "is the tank ready for coral" you'll need to be the final judge of that. You might be perfectly safe putting coral in there, but you might not. I'm just suggesting patience and restraint.

I only have a couple years of experience with reef tanks, but I kept FW for two decades. In both situations, the ONLY things that happen in a hurry are very, very bad things ;) I've noticed.

[jtma508]

Keep in mind, you have a relatively low bio-load at the moment so the various nitrifying bacteria have established a population consistent with the levels of NH4/NO2/NO3 in your tank. How deep is your sand bed? In a 150, 140lbs doesn't seem like it would be deep enough for a DSB. The vast majority of the NO3 fixing bacteria are anearobic and live deep in your sand bed. Very little NO3 fixing is done by aerobic bacteria that live in and on your LR. Do you run a refugium w/macro algae?