Populated Tank re-cycling

[Walla2GSP]

So I made a big mistake carbon dosing and basically recycled my tank. As I've said on here before, I'm taking my old coral tank that has been a refugium for the last 18 months and trying to get it back up to reef-ready status. Because it was a refugium I was dumping all my nitrates and phosphates into there from my FOWLR. So, my first step was to get nitrates and phosphates to safe levels, move half the macro to the sump, and get a clean up crew. I dosed the tank with VSV for a few days to make the levels safe for Invertebrates, then ordered the CUC and a Haitian condy. The problem is after I stopped dosing, the nitrates and phosphates continued to drop and have now been at 0 for a week with everybody in the tank. The day after levels first hit zero, Ammonia spiked briefly in the tank to 3ppm then came right back down to .25ppm, then 0 for the rest of the week. I tested tonight and levels are:

pH: 7.9
Ammonia:0-.25 ppm
Nitrites: 0 ppm
Nitrates: 0 ppm
Phosphates: 0 ppm
Calcium: 450 ppm
Magnesium: 1480 ppm
dkH: 14
Salinity 1.024

It appears to be slowly cycling back to normal on it's own, but is there anything I can do to help it along that won't cause any sudden spikes? I still have some macro hanging around can I safely remove some of that so it's not pulling so much of the nitrate and phosphate out of the water column?

[mcgyvr]

I'm confused.. Has the tank had water/macros,etc.. in it for 18+ months?
Or are you starting fresh?
so old dry rock,etc...?
Sorry I don't want to search for your life story here :p

[Walla2GSP]

It has had macro and water in it for 18 months, and apparently some mushroom corals I had thought were dead a long time ago. Everything chemistry-wise was fine when I started cleaning out the macro and setting up a 20 gallon sump, other than nitrates and phosphates being completely out of control. The live rock is still in there from being a reef tank, and is purpling up now that the macro is gone. I did add a DIY rock stand/shelf about a month ago, but I didn't see any change to the chemistry when i did that other than a 0.1 increase in pH.

[Tisbe]

Lets get an idea of the problem. How did you recycle your tank carbon dosing? What test did you use and did you test with a second kit? Did you do a water change?

At this point it sounds like things are going in the right direction. Personally I would watch it and just do my normal maintenance.

[Raintree]

Sounds like something probably died and caused an ammonia spike. If you are sure your test kits are working properly then i'd say just continue with normal maintenance.

[schnebbles]

what do you mean carbon dosing? I'm new and don't want to make a mistake

[Walla2GSP]

Lets get an idea of the problem. How did you recycle your tank carbon dosing? What test did you use and did you test with a second kit? Did you do a water change?

At this point it sounds like things are going in the right direction. Personally I would watch it and just do my normal maintenance.

I recycled the tank by adding too much VSV and the beneficial bacteria outnumbered nutrients in the water. I have two different API test kits, they talked it out and both agree I screwed up. I didn't do a water change because nothing justified doing one yet.

Sounds like something probably died and caused an ammonia spike. If you are sure your test kits are working properly then i'd say just continue with normal maintenance.

This may be true with the tank being so neglected for so long, but everybody I put in the tank is accounted for, and I don't see anything else that I would consider freshly dead.

what do you mean carbon dosing? I'm new and don't want to make a mistake

Carbon dosing is essentially adding a carbon source, which the beneficial bacteria need for converting nutrients to nitrogen gas, to the water column. There are a few different ways to do this all with benefits and drawbacks, Biopellets, sugar, vodka, vinegar, VSV(Vodka Sugar Vinegar), NOPOX, and others. It kinda supercharges the Biological filtration, but if you screw it up levels can be thrown out of wack which is what I did because I tried to hurry it.

[Tisbe]

Wall I would not consider this a big mistake. Those are the ones that wipe a tank, this is just a learning lesson. :thumbsup:

Something definitely died, probably several things in a chain. Typically when people overdose on carbon they see cloudy water due to the increased number of bacteria in the water column. The concern comes when they decompose and rob the water of oxygen starting a chain reaction killing more things. At this point a water change is typically recommended to quickly reduce the concentration of crap in the water(bacteria, nutrients, etc).

I really would not put anything in to help speed it along. Yes, you can take out the algae but you may see nitrates raise a little but should not be a problem.

[Raintree]

What kind of skimmer do you have on the tank? I'm thinking maybe the skimmer couldn't keep up with the bacteria from the carbon dosing, leading to what Tisbe described