Saltwater Plants

[itafx]

I started a saltwater tank when we went to the beach for a week. For plants, I used 4 kinds of seaweed that washed up in the tide. For a week and a half it was wonderful. Then I noticed that one of the kinds of seaweed is dieing and rotting at the tips and water is being pickled a brownish color. The animals in there are doing fine. I'm not too worried about the tank because it was virtually no cost. But I would like to keep things alive if I can. Maybe there are certain kinds of seaweed that don't do well in tanks. Does anyone have experience with these issues?

[WaterPond]

I think you should probably include what kind it is, maybe a picture?

[melosu58]

Also what are your tank parameters?

[lando]

Can you give us some info on the tank? Size, filtration, age, cycling method, temp, Ph, NH3, NO2, NO3, SG, type of macro or seaweed, etc. Far too little info to offer any useful advice right now.

[itafx]

Here is a pic. The temp is 74 degrees. No fish. Only a couple sand crabs and a few sand bugs. Ph is 7.8, but I wouldn't think that would be the problem because the water and sand are from the place where I got the plants. Another symptom is that the plants used to stand straight up, but now they are weeping over in a pile.

[pinkie]

Looks rather dark in there, what type of lighting do you have?

[Lance M.]

What type of filtration do you have? It's possible the pH was higher before and is decreasing due to lack of O2 exchange.

Do you have a heater in there to keep a constant temperature?

Did you cycle the tank? or just put all of it in there?

Can you test for NH3, NO2, NO3 ?

[itafx]

I don't have much light, but I don't think the plants have had time to react to the light one way or the other. It's a 20 gallon tank and I have 13 watts on it. I could easily change that around and increase the light.

I'm not using a heater since it's summer and one is not needed. The temp is 74 degrees.

Did you cycle the tank? No.

Can you test for NH3, NO2, NO3. Not readily, but I would be surprised if it was very high since I just recently put the stuff in there.

[Lance M.]

For a 20 gallon I think the minimum you would want for lighting would be 40 watts, I keep corals in mine with 130 watts and I would like more light on it.

No matter what time of year it is you want a heater in there just to keep it stable. It may never come on during the day, but when night comes and the temperature drops the tank tank will most likely drop and you want no more than a 2 degree sway from day to night.

The tank could be cycling.

I wouldn't be surprised if your NH3 was high. From your description of the seaweed it sounds like it is dying or dead and rotting in the water. Also the sand and water right on the beach is full of polutants, less so if you go away from populated beaches but still poluted. When they collect ls and natural seawater it's off shore to make sure no polutants.

[lando]

To actively sustain life in the tank, you will need to cycle it properly first. The addition of any organic matter to the tank can cause rapid spikes in NH3 and NO2. I suggest you test for them.

Using sand and water from the beach is not really a great idea. They can contain pollution that is not good for your tank.

Not sure what type of macro you have, but I am betting it will need much more light then you currently have. A higher-penetrating light such as CF or VHO will also be needed.

I hate to be the bearer of bad news...but it looks like things are not really off to a great start.