My Corals haven’t grown in 12 months, what am I doing wrong?

[ReefKing101]

Why haven’t my corals grown in 12 months of owning my tank?

I’ve had my 20g for almost a year now and I’m not lying when I say my corals have pretty much not grown at all. They have survived but barely grown. My gsp has probably grown the most but even that is maybe half an inch in 1 year with maybe another 20 heads. which is ridiculously slow

my tank is covered in corraline algae so this makes me think the alk has been ok just through water changes?

-only just started dosing recently

I test water quite regular although I admit I have been extremely slack the past few months and only just now taking care of the tank again. but the one thing I think might have caused it is not having an ATO the salinity swings like crazy on a day to day basis and I’m thinking maybe this is to blame? I havent fed corals.

couple months ago my phosphate was at 0.70 but managed to bring it down to 0.05 but tank is still filled with algae so not sure if that is to blame.

Could it also be my light? I’m just using a cheap $50 light from Amazon but it has decent reviews and looks alright. Maybe lacks the right spectrum?

Marine Aquarium LED Light Saltwater Fish Tank Coral Reef Growing Lamp 30W | eBay

Features: -Painted metal adjustable bracket, special design for Nano tanks. -Acrylic lens ensure higher light efficiency and remarkable color uniformity. -Mimic the deep-sea environment, help coral to pop and bring out the colors. -Lighting intensity can be adjusted from 0% to 100%, easy to dim...

www.ebay.com.au

 

[saltwaterjunkie12]

If you can provide more information that would help. PH level, calcium level, Kh level, temperature.

 

[ReefKing101]

If you can provide more information that would help. PH level, calcium level, Kh level, temperature.

I can really only provide current parameters as I’m not sure what they were months ago.
Ph 8.5-6
Temp 28c
Alk was 6ish recently raised to 8
Calcium always seem high at 450ppm
Magnesium seems to always read 1900ppm. Red Sea test kit.
Phosphate 0.05
Nitrate 0
Salinity 35ppm
First started tank with Red Sea salt, converted to coral pro salt for a few weeks now back to Red Sea salt

 

[dwest]

I think you are on to the 2 likely causes. An ATO will be beneficial to the tank and make the hobby more fun for you. Do weekly 10% water changes. If that doesn’t help, learn more about your light. For example, I would want to know that it provides at least 50-100 PAR at the bottom of the tank. I don’t know anything about your light.

 

[ReefKing101]

I think you are on to the 2 likely causes. An ATO will be beneficial to the tank and make the hobby more fun for you. Do weekly 10% water changes. If that doesn’t help, learn more about your light. For example, I would want to know that it provides at least 50-100 PAR at the bottom of the tank. I don’t know anything about your light.

I’ve always had a suspicion it’s not good enough for coral growth but reviews say they have had success with coral so I’m just not sure

 

[dwest]

I’ve always had a suspicion it’s not good enough for coral growth but reviews say they have had success with coral so I’m just not sure

You might want to throw out a separate thread specific to the light to see if someone has PAR data on it. Or rent or borrow a PAR meter.

 

[Uncle99]

The ATO is a critical piece of equipment as changes in salinity affect other parameters and creates an unstable environment.

 

[dvgyfresh]

Those lights are fine - old tank with lights (I switched to orphek) it’s something to do with stability

 

[Lowlandreef]

I can really only provide current parameters as I’m not sure what they were months ago.
Ph 8.5-6
Temp 28c
Alk was 6ish recently raised to 8
Calcium always seem high at 450ppm
Magnesium seems to always read 1900ppm. Red Sea test kit.
Phosphate 0.05
Nitrate 0
Salinity 35ppm
First started tank with Red Sea salt, converted to coral pro salt for a few weeks now back to Red Sea salt

Just wanna check, is your temperature really 28C?
It should be around 24-25C. I've had a temperature spike in the summer to 27C and (some of) my corals had a really rough time in those few days before I was able to lower it down.
If it really is 28C, I would highly recommend to lower your temperature asap.

 

[ReefKing101]

Just wanna check, is your temperature really 28C?
It should be around 24-25C. I've had a temperature spike in the summer to 27C and (some of) my corals had a really rough time in those few days before I was able to lower it down.
If it really is 28C, I would highly recommend to lower your temperature asap.

Ohh dam, yes it’s always been 28+ I’ve got the dial set to 27 on my eheim jag but it always stays around 28. I will try lower it to 26c

 

[ReefKing101]

Those lights are fine - old tank with lights (I switched to orphek) it’s something to do with stability

You had good coral growth with those lights?

 

[dvgyfresh]

You had good coral growth with those lights?

Yea , grew sps,lps, and softies

 

[Tamberav]

What size tank is it?

 

[TISLE]

A couple of your parameters seem a little off to be honest along with stablity issues from what you seem to be conveying. Though you want "lower" nitrate, if what your saying is true that you recently starting dosing 2 part you could of been starving your corals not inputting enough nutrients. Corals need nutrients. Having them at 0 - and if they are truly zero - is almost worse off then having them over a threshold of the higher end of what is accepted. I ran a ULNS for a while before ditching it for higher nutrients. Why? You have to supplement far far more in almost every retrospect. Also it seems as though your tank isn't super stable. Stability is the key recipe for a successful reef tank. People have ULNS, high nutrient, too "high" or too "low" of this or that thats not the quote on quote "norm" but they grow coral like crazy. Its because of long term stablity. Things might be a bit off but its always like that and it just works so why tweak it? Id reccommend investing an ATO - you can get them super cheap in the used sale threads on R2R often - also invest in some solid test kits and test every week. Dial in your numbers and keep things as stable as they can be. If you keep your tank stable at good enough levels and your corals are getting enough light & nutrients they WILL grow.

 

[Joekovar]

I would drop the temperature to 25c, hook a fresh air line from outside to the skimmer, and slowly bring alk up to 9-9.5 until that magnesium starts coming down. Keeping an eye on calcium and keeping it around 450 in the process. Once the magnesium gets to 1300-1350 I'd bring alk down to 8.5.

Coraline algae is better adapted to global warming type conditions than corals are. Coraline produces dolomite which is 50% magnesium vs the aragonite that corals produce.

If coraline is thriving and corals aren't, temperature and high co2 should be the main contributers.

 

[Just John]

This sounds like my first tank experience from a long time ago