Cycle issues?
 

I have been waiting for my new system to finish cycling since the prawn went in November 27. It still has nitrates in the range of 25. Here's the system and what I have done so far.
90 gallon Display drilled with 2 1.5" drains, 1 1" return, 33 gallon sump, bubble trap, live rock in sump, Vertex 250 skimmer. Display has live sand (about 3" Carib Sea Fiji), about 180-200 lbs of live rock. Live rock was bought from an established 200 gallon system, went into a food safe garbage can with heater, powerhead, saltwater to cook. Was cooking from June to November when it went into the display. During the cooking I did check nitrates for something to do and found about the same levels right up to going into the display. Now I didn't check ammonia or nitrites during the last 2 months but the LFS store did. At 9 weeks to try to get it to finish off we did a 50 gallon water change and threw in a 500ml bottle of Cycle. Week later nitrates are still the same….:frusty:
Am I just impatient or is there something I should or shouldn't have done?

When you say a 500ml bottle of Cycle, what brand?

Nutrifin.

I would never use that for a cycle as its made more for freshwater. Should have used Prodibio Startup as its made for saltwater tanks. I cycled my 300 in 2 weeks with new sand, dead rock and new saltwater.

Good to know. That still doesn't explain why after 8 weeks (pre-cycle additive) the nitrates haven't moved. If nothing has changed in the next week or so maybe i should try that brand.

Did you do water changes through out the cycle? Is your skimmer off? Or maybe its a bad test kit?

You haven't mentioned what your PO4 is at, or what levels you had when you were 'cooking' your LR before you introduced it to your system
When you 'cook' LR, you are best to reduce it to zero readings of both N03 and PO4; of course well beyond NH3

If you cooked your LR properly you would have been doing regular weekly water changes to remove the stuff you didn't want in your DT
Having an N03 reading as high as your's leads me to believe you didn't fully cook your rock
Plus, IMHO, having that much rock (180-200lbs) is enough for a 400+Gallon system. You haven't stuffed all that LR into your 90G tank, have you ?

3" of sand is a lot. In my opinion, you're in between a regular 1" bed and a 'deep' sandbed. Do you need that much ? Others will speak up, but I'm thinking it's too much of everything, and it needs some re-thinking ...

I'd suggest you remove a whole lot of that rock, such as reduce it down to maybe 90-125lbs, and then you'll still have to 'cook/cure' it before you can stabilize your N03 readings
Plus you'll actually have room for corals

Get that rock down to zero readings for both N03 and P04, then you can start building a great tank

But this is just my opinion based on what I've read here and what I've done, so take it for what it is ...
Good advice from knowledgeable/opinionated people :wink:

WOW how did I miss that!! 3" of sand and that much rock in a 90 is way to much IMO as well, I would have to agree with gregzz on his assessment.

I don't know what the PO4 is in the display or what it was in the LR pot. I did 3 or 4 water changes during the cooking so I guess not enough… yes :redface:
I do have most of that in the DT, probably about 30 lbs in the sump from the 200. The tank is between my family room and office so dual viewing. I have a established 55 gallon as well that is shy of rock so likely some is destine for it. I welcome the advice hence the posts as I took over the 55 (abused tank and critters) in May so still very new to the hobby.

Thanks Greg :smile:

I'm not sure if I gradgeated, but I went through the 'School of Mindy'
She was there for me throughout my whole initial planning stage and I can't thank her enough :wink:

Plus I learned a whole bunch more from all of us CanReefers, so many more get credit for my limited knowledge ....

Persistant, I'd recommend the linked Mindy info if you haven't already read something as informative

Good luck !! :biggrin: