My 18g sps dominated - need second opinion

[ormet]

Hey, im rather new to SPS keeping, i started my tank december 2011.

Since then i have had moderate success. Not much has died, some things grows well but most is growing fairly slow and some are not growing at all. Also, i tend to have either brown or somewhat pale colors.

I get better growth (but not on all corals) with longer light periods, but corals get more pale. If i adjust light periods way down, corals get better colors but no growth.

That is my problem for the time being. What i want, of course, is good, fast growth and nice colors.

I have a thread active at a swedish SW forum and the advice i have gotten so far are:

1) raise po4, its to low.
2) stop dosing balling and see what happens.

With this said i hope to either get the same answers here to consolidate it or better yet get answers more to my liking

First some technical info, parameters and history.

It is 18g with 8g sump. 24"x15"x13" (LxWxH)
It uses a SWC 160 cone skimmer
It is bare bottom
It uses a Tunze 6045 for circulation, wide flow modded.
For lights i use a ATI sunpower 6x24w T5 HO tubes.

I dose balling light including trace elements using a bubble magus dosing pump.

I have CAG in a mesh bag in a high circ area, 0,5 deciliter (cant be arsed to convert for you) changed monthly.

I have eheim ehfi mech in 2 mesh bags in high circ area of sump as biological filtration.

i dose VSV, fauna marin amino acids (ultra min s) and organics daily. i sometimes dose NaNO3 to raise my No3.

Ca: 430 - been stable for a few months
Mg: 1260 - also stable
Alk: 7,3 - has varied wildly. 10 weeks ago, it was almost 12. adjusted dosing, 3 weeks ago i measured 3,6. now i manually dose 1 extra dose every evening and it has been 7-7,5 for a week.

po4: 0.00 (hanna checker) - had 0.05 as highest since i started doing bare bottom.
no3: 7,5 - i have always had 0 but started to dose NaNO3 a week or two ago.
Salinity: 1.024


Actinic light: 11:00-21:00
Full light: 14:45-18:30 - i ran full light for 6 hours in may, but everything went bleached. Went down to 3 hours which helped with colors.

Also worth mentioning, i have some algea on my fake rocks where detrius collects and also some slow growth on my glass. i usually clean the glass every 3-4 days.

I have 3 clowns, 2 fire gobys, 1 amblygobius hectori, 1 plectranthias inermis and 1 Stenogobiops nematodes. I feed these a few pinches pellets and one half to one cube frozen mysis shrimp or other frozen food.

I have some pictures and a newly shot video for you.

These have shown some healthy growth.

If the stylo has grown or just looks bigger with the crazy PE i dont know

In the video below, the brown/pinkish/green acropora grows very slowly and the pociliopora hasnt grown at all. My blue staghorns and green slimer wont grow either. The full tank shot is a bit off in colors, individual coral close ups are fairly accurate.

http://www.youtube.com/watch?v=exMeKKQf1kM

I will be very grateful for your help and advice
regards
Daniel

 

[plyle02]

Nice video, I think the health of corals is there, I think I would up the fish feedings a bit, looks like your system is too nutrient starved. If you feed once per day, try upping to 2 times per day, or maybe 3, given barebottom, little rock, no collection areas of detritus, powerful flow and skimming, your tank is processing nutrients before the corals can feed off the fish poop. When I ran bb, I had to feed many more times per day because of the quick nutrient export. HTH's

 

[karsseboom]

I think alk is the most important thing to watch in an Sps tank. If your alk is not steady then that could be the reason for the stn. The corals don't look like the kind of
Pale that is caused from low nutrients and more like the po4 might be high.

 

[ShaunMonahan]

Nice tank! One piece of advice I can give is to focus on stability in such a small system. If you keep your chemistry even and consistent, you have the results you are looking for.

 

[ormet]

thank you for your feedback and your appreciation.

I think maybe its as easy as to focus on stable parameters (duh) and provide more food for my corals. More fish, more fish food, more poop! and maybe some specific coral food.