My 29g

[DustinB]

What salt are you using? I've never had to buffer a tank for pH and mine is always at 8.3.

[fishboyt]

I'm using Instant Ocean. It says it maintains the proper Ph which makes me wonder if that is the problem.

[fishboyt]

Temps are 81/82.

[DustinB]

Same salt I use, I doubt that's a problem. How long has the tank been running? Was that rock from an established tank?

[fishboyt]

About 2lbs. of it was. I made the rest of it.

[DustinB]

What did you make it out of? How long did you cure it?

[tang-chaser]

ok Heres the just of what im getting.
1)If your rocks were diy and not fully cured your ph would be higher.
2)If you added more live rock and it wasent fully cured, it could raise ammonia lev and cause the tank to go through a small cycle again.
3) try to drop your temp down to 79-80 your a bit on the high for me
4) your ph maybe low because of overfeeding or to much decoposition in tank.
5) have you ever added a little bit of magnesseum? this will also help raise/stabalize ph, But do it sparingly like any other chem you would put in.
6) Stop restocking the tank so quick. If one thing dies wait it out a bit. Only add litle by little. The faster you go the harder you will crash the tank.
7) is your powerhead moving water at the top of the tank? you want surface movement to oxigenate the water.
8) check your salenity. salentiy has been known to effect the ph also due to the menerals in the salt mix.
9) check ph in morning and afternoon, because it will shift durring the day.
Thats all i can think of right now. Hope this can help.

[fishboyt]

What did you make it out of? How long did you cure it?

Portland cement, rock salt, and oyster shells. I let it cure for about 1.5 months.

[nacra99]

..., so I just did what the lady at the LFS said to do by buring him in the sand. ...

WHAT!!!!????
Ok.. that's the worst advice that anyone can give. Especially for a newly established tank.
Some people use dead fish in order to provide ammonia to cycle the tank. If that is the case, the dead fish would have kicked up the ammonia concentration and kill everything.

[nacra99]

Hey T,
Don't take this the wrong way, but in my HUMBLE opinion, I think you are going at it a little fast.
Newly established SW tank tends to be very unstable. Here are my obsevations.

1. You have 2 lb of live rock for a 29 gal tank. IMHO, way too little to support a good colony of established organisms and bacteria. Unless you are doing WCs everyday, I would try to add at a bare minimum 1/2 lb per gal or if you can, make it 1 lb per gal. Established liverock have established bacteria and are far more resilient than freshly formed bacteria on new "dead" rock. Furthermore, besides supporting a variety of bacteria which assist in the nitrogen cycle, establised live rock support lots of other critters and bugs which do various jobs in keeping the tank clean and water stable.

2. Rock salt in your DIY Rock. Rock salt is mixed into the concrete so that when it dissolves, it makes nice and pretty holes in the concrete rocks making them look more natural. Check your S.G to see that your specific gravity is correct. Salt might still be leaching out of your diy rock into the water causing the salinity to rise. don't let it go more than 1.023 - 1.025.

3. Temp. If possible, keep it 80 or less. With your lighting + summertime temps, it might overheat. 79 would be best.

4A. Stocking time. It is my opinion that you might be going a little fast on this one. Thankfully most of the coral that you picked, especially the rics are pretty hardy and should do ok. But for a newly established system, it would be better to add pieces a bit at a time at least a few days apart, always testing the water between additions for ammonia and nitrItes. I wouldn't add ANYTHING to the tank until both are ZERO.

4B. Nutrient balance. I also notice that you still have a lot of diatomic growth (brown algae) when you added the perc. This to me, indicates that your tank is till quite "young". As a [VERY] general rule of thumb, i usually tell people that after the brown algae, comes the green algae and then comes the crusty purple (coraline) algae. To be safe, don't add anything until the brown algae starts to disappear and the green algae comes in. That usually gives enough time for the tank to settle down.

5. Something is buffering your pH to 7.8. It is not the concrete because portland cement cures at pH 9-ish. If anything, the cement will cause a pH rise. There are many ways to fix this. The simplest and safest thing to do is to get either oyster shells or crushed coral. Stuff it into a filter bag and stuff it into your sump somewhere where you get a lot of water forced to flow into the bag.

Take it slow and don't get discouraged. Many people quit SW as soon as they start because they try to do it like FW systems and fail. SLOWWW........ is key.

[soymilk]

I bought a used pump and plumbed it into my system once. I'm not sure if there was something in the pump or if I didn't properly wash my plastic fittings from home depot, but my tank was crashing hard. Replacing the pump/fittings and doing an emergency water change helped me. Seemed something leeched into my system.

Not sure if any of this helps but becareful adding anything new to your system.