75 gallon flow and nitrate question

[amylynnfloyd]

I finally added my first fish to my display tank. My tank has been up and running for about 2 months now. The ammonia was 0, Nitrites 0, Nitrates 0, and everything has been looking very good. I purchased 5 small green chromis from live aquaria, and they sent me six of them. I added them yesterday and everything seemed to be going ok. They were acting a little more scared than I expected, but I thought this was probably due to the stress of being moved from one tank to another. This morning 4 were hiding in the rock, and I could not get them to come out. The other two were hiding behind the powerheads. One of which was having a very difficult time swimming. I turned the powerheads off after a couple of hours, and they instantly all came out and began swimming around like normal. They are eating now and doing great. I have two K4's in the aquarium which is 75 gallon. Is this to much flow? Should I drop to K3's or K2's? This morning I checked my Ammonia which is still at 0, Nitrites are still at 0, but Nitrates have jumped to 15-20ppm. Is this normal after adding fish? All of my inverts seem to be doing ok. I have several snails, hermit crabs, and a couple of shrimp. I am planning on doing a 10 gallon water change this afternoon. Is there anything else that I should do to drop the nitrates? Thanks

 

[rfd515]

That seems like a lot of fish to add all at once to a new tank.

 

[amylynnfloyd]

Yes, I agree, I am still a little concerned about adding 6 of them. I am planning a lot of water changes. So far no Ammonia spike, which was my main concern. I have been testing like crazy. As long as I can keep nitrates down with water changes I think they are doing fine. How much water should I change at a time? Also, I was planning on doing a small change every day, is that the way to go? Any advise about flow?

 

[Gold Stripe]

2 K4s is quite a bit for a 75 gal (4ft) tank in addition to return unless you are going to have an SPS tank. I probably would have gone with 2s or 3s. Its not so much the flow as the force that causes the problem.

Also, 6 fish is a lot to add to a new tank. You have to give the tank time to catch up to the bioload. The good thing is that your tank seems to have processed the amonia and nitrite quickly and turned it into nitrate which is not as harmful to fish as it is to corals. I would do a water change and just watch. Then only add 1 fish at a time so the tank has time to adjust. If you are not running a refugium with macro or an established DSB then you are just going to have to combat the nitrates with water changes.

 

[amylynnfloyd]

I am thinking about selling the K4's and getting 2 K3's. I went with the 4's because I eventually want to keep SPS. Will I still be able to keep SPS with 2 K3's?

I am in the process of setting up a fuge with macro algae, but I am still about a week away from that. I am not planning on adding any more fish for at least a month or more. I am running a deep sand bed that is about 5 inches deep, and 140lbs of live rock which I cured for about 5 months before adding it to my display. I will try to get my fuge up as soon as I possibly can. Thanks for the response.