attempting to lower nitrates w/ a DSB worried about chemistry after install

[jksmiley]

I recently moved my stock and 60% of my LR to a 10 gallon Q-tank while a newly installed DSB settles and the water clears. Two concerns.

1. I was told that since the new sand is covering the old sand that the tank must cycle again. The new sand added 2.5 inches (5 total now) to the bed depth. Is the statment regarding cycling true?

2. If the tank does indeed need to cycle, what signs if any are there that this is the case and how long will it take since the tank is 1.5 years old already? I noticed a great deal of worm activity in the new sand and I'm hoping that they are distributing the SB fauna throughout the new bed.

I have a flame angel that I would like to return to my main tank ASAP but I don't want to move her if the tank is unstable.

Recomendations?

[Randy Holmes-Farley]

jksimiley:

Is the new sand live or dead? If it is live, there will be a cycle from things on the sand dieing in transit to your tank.

If not, some things may die in the lower, older sand bed, and that may cause a cycle.

You can monitor a cycle with nitrite and ammonia kits. If you don't detect either after a few days, you don't have a problem. If you do detect them, wait until they have disappeared.

[jksmiley]

The sand is new and it's argonite. You can get it for 20.00 a bag if any readers are interested (30lbs per bag from a local store here in NC). I've seen the same bag for 40.00 everywhere else.

[billsreef]

jksmiley

Just give the critters a couple of days to mix the sand up. Do some water tests for NH3 and NO2, if they are good than you can put your flame angel back in. BTW I do this fairly often myself to culture LS and find things go back to normal fairly quickly.

[dragon0121]

If one were to follow Dr. Ron's advice on adding new sand to a sandbed, then adding 2.5 inches is a major no-no :D . Usually 1/2 inch at a time is recommended giving the critters in the existing sand time to crawl up into the new sand without suffocating. 2.5 inches will probably result in the die off of a lot of the life in the old sandbed, hence a cycle of some sort. I've added sand to my sandbed a couple time, shooting for the 1/2 inch layer, and have never had a cycle take place.

[jksmiley]

I'm on day 3 after the change without a change in chemistry. I pulled the old biofilter in the milenium 3000 filter I have had since dirt. It was used before the LR was added and now is used for its carbon filtering ability. Listed below are the chemistry readings and my plans. If anyone has some ideas on what to do to further decrease my NO2 I will gladly entertain them.

Chemistry:

NO2 : 0.3 mg/L (been like this for a year)

NH3 : 0.0

pH : 8.5

Carbonate Hardness : 11 dH

Ca : 450

I plan to remove the biofilter permanently, add another 10 lbs of LR, and upgrade the skimmer from a prizm to a lifereef unit.

The sandbed is now 4.5 to 5 inches in depth. Is this deep enough to function as a nitrate reducer?

The ultimate goal is to provide a stable tank for coral (a new venture for me).

Oh, the lighting is 2 96 watt PC = 6.4 watts per gallon.

[Randy Holmes-Farley]

jksmiley:

Do you really mean that you always have detectable nitrite (NO2-) or do you mean nitrate (NO3-)?

4-5 inches is more than enough for nitrate reduction unless the sand is very coarse.

[jksmiley]

My apologies, the test is for nitrite (NO2) and not nitrate.

[Randy Holmes-Farley]

I hope the nitrite reading for a year is a kit error. You really shouldn't have nitrites around. Nitrite is quite toxic.

[billsreef]

A simple way to test your kit is to test some nice pure RO water ;) Most hobbyist test kits I find tend to give false high readings when the reagents are over the hill.