'Grass advice for 'Bermuda

[Samala]

Ok here are some quotes from your website. I am in the process of setting up a new mud sump and wanted to pick your brain a little and see what kind of successes you have had.

"The seagrasses all need considerable depth for roots and rhizomes and come from anoxic soils, so recreating this is probably best. Considering this I'll be building a substrate of a minimum 5" depth with a top layer of aragonite sand for buffering purposes."

Question:
What kind of results have you had with aragonite/mud mix? I am thinking about setting up something similar. Since I live in Dallas, I don't have the luxuries of having natural mud at my disposal. I am going to mix a 50/50 substrate of miracle mud and aragonite for the sump.

"I am going to experiment with Seachem's Flourish Excel, which is a liquid carbon source, and see later if the amout of CO2 given off by the horses is enough to keep the seagrasses going."

Would it be safe to use the flourish excel in a reef tank?

Okay, first things first, since my crazy little peice of the web progresses in weekly/monthly logs and updates of the tanks I post things I'll do and then tend to follow up on them as things progress over the ensuing months. So, sometimes things stay posted that I eventually abandon, or find to be flawed, or dont work perfectly. I could edit out the failures but I think I learn more from being reminded what I've done wrong, and what I've done right.

Some things I've learned about the seagrasses do support that early statement about needing deep and rich substrates, just as you will find this kind of info in the hobbyist online articles. (Calfo wrote one even.) About 4" for manatee, shoal and the small grasses, up to 6" for turtle grass. Natural mud has been working nicely, but I'm not sure about using miracle mud.. I have no experience iwth it at all. Anyone else have an idea?

Otherwise, simply having an old DSB to take some substrate from seems to kick start a 'grass bed. I have had great results with the grass even in only-aragonite beds but you have to set up the tank as a planted tank.. meaning you will eventually be adding nutrients into the tank to support the plants. Having the nutrients in the substrate helps seagrass survive in the nutrient poor conditions of a lagoonal system or in line with a reef system.

Fluorish Excel, we just had this come up again recently.. see Reggae's post here. I would not use this in a reef tank. Too many unknowns. I am not even currently using it in my 'grass tanks.. all the needs are being met in other ways.

Anything else? Happy to help if I can.
>Sarah

[ScubaBermuda]

Thank you very much for the info. Very helpful. I read the post.

I do have 1 more question, a bit off subject.

I recently added some Chaetomorpha to an existing sump with supplemental lighting to experiment for de-nitrification purposes. The sump is supplemented by a skimmer and I run the lights on a reverse cycle. There is no mud at all involved. Just a sand bed in the main display tank.

I have had lots of success with this method. However, one drawback that I have had is that I am have big swings in my PH. Since the addition of the Chaetomorpha, I have a hard time keeping the PH above 8.1

Now, I have talked to several people about this, originally I was told that the C02 concentration may be high in my tank. Well the supplementation of a skimmer alleviates this in my opinion.

Any suggestions here? Do macros lower PH in general?

Thanks.

[piercho]

Do macros lower PH in general?

Not when they are exposed to enough light. The plants, in effect, pull CO2 from the water, often faster than gas exchange between the tank and air can keep up with. As CO2 exchange lags, pH rises.

So, the addition of producers to the tank should drive O2 up and pH up. Its respiration that tends to drive pH lower.

Persistent low pH is often seen in tanks using calcium reactors. It is sometimes seen in tanks in tightly sealed homes where the air is high in CO2. It is frequently seen in tanks with a large fish load.

[ScubaBermuda]

Thank you for taking the time to explain. I really do appreciate it.

[Samala]

Thanks Piercho, I musta missed that last post! I would also recommend looking for another cause of the depressed pH.. I, like Piercho says, have a hard time keeping my pH down not up. I would keep an eye on your alk levels, perhaps with the addition of the Chaeto you have alkalinity being consumed at a faster rate than before. (?)

>Sarah

[ScubaBermuda]

Well, I have an update for the both of you on this subject.

Originally I experimented with removing my skimmer and running the sump with cheato supplementation only for de-nitrification. All hell broke loose. I assume that the dissolved oxygen levels in the tank dropped significantly and I also have to assume that the level of nitrates spiked. The macros might have had a hard time keeping up. I did have a healthy amount in the sump. I do have a reasonable bio load in the tank as well. 140 Gallon tank with 4 grammas, 2 clowns, 1 purple tang. I should have tested the water but for some dumb reason I did not. The combination of these effects would de-stabilize the ph in my opinion.

I implemented the skimmer last week after being too worried about the ph levels going up and down in my tank. Sure enough ph has stabilized around 8.2 now.