New SW using Aqua One 620- help??

[DI68]

Hi

I have a couple of (what I think are awesome ) cichlid tanks - 215litres (56 gals) and 308 litres (79 gals) and have decided to venture into SW with my 90 litre (23 gals) Aqua One 620. This is a complete unit with filtration and lighting in the top hood. I have recently replaced the lights with the 18watt marine/sunlight fluorescent globes.
I have a very shallow fine coral sand bed ( about 1.5- 2cm depth)
7kg premium live rock- there was some die off happening when I first put it in the tank.
2000litres per hour Resun wavemaker
Aqua One powerhead 550 litres per hour ( comes with the tank )
Heater
Hydrometer
Digital thermometer as the heater is giving the wrong readings- current temp is 25.8 degs although the heater is set at 20 degs
Natural salt water and Ro/di water for top ups

It has been running now (cycling ? ) for 3 weeks and my water parameters aren't right:

Nitrate 80-160 ppm ammonia 0 PH 7.8- 8 nitrite 5.0
Any help on how I achieve the right water to add anemone and fish?
Is cycling just letting the filter run? What else do I need to do? I have never had problems with tropicals and cichlids so am reading so much more into SW requirements before adding fish.
I am also concerned that the filtration may not be enough. I have a thin white mat, noodle media and the course black mat on top and getting confused the more I read as some people use carbon, add protein skimmers and a chiller ( I have a chiller as it gets hot here but would have to take the back filtration off to hook it up? ). I have attached pics of the filtration and set up so far. I have concerns as the water runs back out near the power head as the levels are high. Even taking out the media the water height is still high.
Any help would be appreciated as I want to get this right first time around.

 

[Bectan01]

That type of filtration is not really suited to a saltwater set up unless you are cleaning it out regularly, that is every couple of days. It is good to add an ammonia source to cycle the tank but you may have had enough come from the live rock. (hence the nitrite and high nitrate) Without livestock in your tank you could still do that, add a raw shrimp and let it rot - test for the rise in ammonia then nitrite then you will have high nitrates at the end do a big water change and you should be set to go. What do you plan on keeping? Check out some of the nano builds on here for tips on how best to run this size, I have a bigger tank so my filtration is different. But I have a tank that size that I hope to make salt too so it would be interesting to see some other people's advice!

 

[DI68]

Thanks Bectan01. I have 4 tanks. The last is empty- I bought it 2nd hand - 3ft traditional timber base and hood. It came with a near new chiller and cannister filter- I just bought it for the chiller and am trying to re sell the tank. Am I better off changing to this tank while in the early stages? I have seen the nano tanks set up in shops so I thought it would be easy til I started reading into it. The smaller tanks seem more finnicky with water spikes.

 

[Cichlid-dude]

Id use the larger of the tanks. I know that whenever i set up a tank a couple months goes by and i already want a larger one. May just be me, but id go with the large one.

 

[DI68]

Thanks Cichlid-Dude. Am running out of space with tanks. If I set up the 3ft tank I can see the AR620 ending up in my bedroom lol