How to make corals grow?

Hi there! Welcome to the forums! Sorry that no one answered this thread when you had it up. It certainly slipped by me. I hope you come back and check on this thread when you get the opportunity to do so.

You have a wonderful lighting system. With that lighting system, you should replace the bulbs once a year. If you haven't done so already, you need to go ahead and do it. Also, if you haven't done it yet, put your lights on a timer, no longer than 8 hours a day. That red algae you have is called cyanobacteria. Cyano is quite common in tanks that have lights on for longer than 8 hours a day, a large amount of nitrate and phosphate in the system, and low water flow. Before your corals can grow and thrive, you need to bring your nitrate and phosphate levels down.

First and formost, when you use tap water, you are adding nitrate and phosphate to your system. Nitrate and phosphate causes algae growth and inhibits coral growth. It can also be detrimental to your coral and fishes overall health. Nitrate and phosphate can also be introduced into your tank by excess amounts of food and bad top off water.

You need to switch your top off water to pure distilled or RO/DI water that you can buy at a water store, grocery store, or your local Wal-Mart. Also, all the water that you mix for your water changes should be RO/DI water. This ensures that you are not adding any excess nitrate and phosphate and other toxins/chemicals/heavy metals into your system. It will also help you start cleaning up your tank and getting rid of that red cyanobacteria algae.

If you don't already have test kits, buy a Reef Master Test kit by API. It has liquid tests for Nitrate, Phosphate, Calcium and Alkalinity. Test your water for Nitrate and Phosphate and then post them in this thread. By doing water changes with RO/DI+salt water, using adequate filtration and the use of macro algaes, you can get these two fertilizers as close to zero as possible. Keep testing weekly after your water changes to see if it's going down. 

When people say that your water parameters should be as stable as possible, this is what they are talking about:

Nitrate: less than 5ppm

Phosphate: unmeasureable (0ppm)

pH: 8.2-8.3 constant

temp: constant. anywhere from 74F to 84F, as long as it's constant.

Calcium: 440-460ppm

Alkalinity: 8-10dKh

Magnesium: 1350-1400ppm

It will take a few months with some real work to start to see that red algae start going away. Cyanobacteria is a real beast to get rid of. Once you start seeing a lot of it receeding, and it's about half as bad as it is, then  you can probably start to use an antibiotic to kill the cyanobacteria like Red Slime Remover. Make sure you read the directions very, very carefully, and prepare a fresh saltwater batch of 50% your tanks volume for a water change 24 hours after you add the antibiotic. If you have too much cyanobacteria in the system and you use the antibiotic , even with a water change you still might risk crashing the system. That's why I recommend getting rid of the cyano the old fashion way - with water changes and macro algaes.

What kind of filtration do you have and what is your internal flow rates? If you don't already have powerheads in the tank, buy a couple of powerheads, like two Koralia 5s and add them to the tank. The extra water flow will stir some of it up and keep it filtered out. You should change your filters out every other day for a little while - rinse them in the sink with freshwater and then put em' back in the system if you have to. Just make sure you are filtering it out.

If you don't already have one, buy a phosphate reactor and buy some granulated ferric oxide (GFO) media for the reactor. This is a chemical way of removing phosphate and other organics from your system. It will also help remove some of that red slime algae.

If you have crushed coral as a substrate, when you do a proper water change with that water I told you to use, gravel vac 1/4 to 1/2 of your crushed coral at your next water change. You'll get some really bad muck out of the tank the first few times you do it. When you can, if you have crushed coral, you should clean it up as much as possible with the gravel vac over the next couple of months and then when it's clean, you need to decide if you are going to keep it and keep gravel vac-ing it or if you are going to replace it with dry aragonite sand. I'de personally go with the sand. There are several threads about how to change your substrate in an existing system. Look em' up.

There are also some very good threads that you can look at that deal with cyanobacteria and hair algaes. Your tank is going to take a while to get back to where it needs to be, but it will if you take a few steps in the right direction. IF you need any other help, feel free to PM me, I'll come back to this thread.

I wanted to add that I have used the red slime remover with great success but like snake said be very careful if you do use it and go by the directions. Adding anything like that to your system could always be a possible bad outcome if not done correctly.

i would also like to add a few things about cyano. if you take a turkey baster and squirt the big stuff daily for a while and scoop it up with a net that will help. cyano can definately live in any kind of flow i have about 6000 gph in my 100 gal. i have an sps dominant tank and have as good of water quality as it gets and i still had cyano growing, once it is introduced to your tank it is self sufficient meaning it produces its own nutrients to live off of. needless to say i treated my tank to get rid of it and i would not treat it again unless i was there to constantly monitor it. and also i would not keep your temp above 80 even if it is consistent algae grows quicker at higher temps and if your having algae problems then thats not good.