Okay, so I've been doing saltwater tank stuff for 3-4 years. My 13 gallon did excellent, my other 3 tanks i had, not so much, so I ditched them and just stuck with the 13. I Never had any issues until now.
It sounds like you did have problems with the other tanks. What problems?
I upgraded it to a 20 gallon because I got the tank for like 10 bucks with stuff included for a freshwater tank.
A concern here would be what was in the tank before you got it. What equipment came with it that is being used? We wan to make sure that copper or other medications were not used that may have left a residue.
So, I did what i usually did got a skimmer and a filter. I didn't know coralife made a 2 in one filter, and the tank is awkward and I have 6 cats so I need a cover for it regardless.
The issue with a full cover is gas exchange. pH and oxygenation become issue quickly. This makes the skimmer and flow so much more important. But we will tackle that after we get a handle on what is going on now, even if they contributed to the issue, they did not cause it.
So I set that filter up. No issues for like 3 weeks. Now, the tanks water is turning green. Even after an 80% water change. I do plan on getting a uv sterilizer, and a new filter. I like having protein skimmers, I've always used one on my small tanks. It just that the tanks a hexagon. My 13 gallon was over taken but GSP so I started fresh in a sense. But with the same water and creatures that were already in it. I have about 2 and a 1/2 live rocks, 2 clowns, mandarin goby, like 4 or 5 snails, some hermits, a pistol shrimp, and a watchman goby, along with an anenome and some emerald crabs. Maybe 1 or 2, and a tuxedo urchin. I have tried a few water changes and I started using RO water instead of tap because I was reading about a lot of different stuff.
Using the old water (and sand?) was the first mistake but there is not much we can do about that now.
Tap water - same thing, but you have RO now, so that will help.
The tank has a very high bio-load given the filtration, minimal rock and lack of efficient skimming. I am going to assume that you are significantly overfeeding and this coupled with the tap water and re-used water and sand has kicked of an algae blook driven by very high nutrients.
Water changes alone are not going to solve the issue at this point.
You may want to re-home one or both urchins. They will eventually starve in a tank that small.
The kits I use are the API master and reef testing kits. I also have 3 other test kits for calcium, magnesium, and maybe dKh, i can't think of which one at the moment, but I have a hard time understanding the directions and how to figure it out so I havent used them. Now, the pH level was 8-8.2. I miss labeled that. But I'll send my parameters over later. I have to test my tank anyways.
Don't worry about calcium, alk or mag right now. We just need accurate phosphate and nitrate tests right now.
The pH is fine, let's not worry about that either at the moment.
Feeding, i also only feed like 3 times a week. I defrost it in a baggy with saltwater and leave it in the tank until it's ready to be served. I only ever had little bits at a time. I use frozen and sometimes flakes, pellets, or seaweed. Depends honestly.
Feeding - 3 times a week is fine for now. A single cube is plenty until we understand the phosphate situation.
I also have a hard time with dosing out my "chemicals" per say, i never know how often, or when, and how much. So i just do it when i change the water or when I add in new things. I'm at loss right now. I've never had a problem. And always did it the same way, but now, its just falling apart. And I'm stuck.
We can work on testing for Calcium and Alk once we understand phosphate and nitrate. For now, don't dose anything else. No alk, cal, mag or other reef products.
The water turned GREEN again today 11/4, when it wasn't last night. I had the lights off all day yesterday but I put the night time light on before I went to bed.
All said and done as long as the setup has no chemical contamination from freshwater medications, You likely have high nutrient levels and it is driving an algae bloom. While it may clear up eventually if we can find the root cause, the easiest way for a tank this small will be to use a small UV unit (9W) from petco that has a built in powerhead. You can turn the lights off for a few days also without harming the fish or corals.
I'll also attach photos when I get home from work as well. I do want to mention that I am a vet tech, I have some knowledge but not too much in a sense. I mentioned this because I have a bunch of people i work with who have fresh water tanks. Any help or advice would be appreciated along with different links and stuff i should buy.
Fresh water experience does not translate very well unfortunately.
Short term steps.
1 - Make sure all water is RO/DI and has low TDS.
2 - Accurate Phosphate and Nitrate tests for us.
3 - Lights out for a few days.
4 - Keep feeding under control.
5 - Spend $30 and get a 9W UV and get it on the tank.
Longer term steps.
1 - increase flow in tank.
2 - evaluate filtration and skimming.
3 - get a handle on testing and alk/cal consumption and easy way to maintain them for that size tank.
4 - Phosphate levels may dictate use of GFO or another medium to reduce them until you get their source under control.
I suggest, at least in the short term using a notebook to log daily testing until you get this under control.
Let is know if you need help with the test kits. Don't rely on the LFS (they make mistakes too) but using them to test your water for a second set of eyes is not a bad idea.
