Plant Growth issue

[Buc_Nasty]

I have two enormous aponogeton plants that are growing extremely fast and green.

The problem is I have some stargrass (about 2inch by 2 inch area) that hasnt spread in 3 months since i planted it. Its kind of green, not super healthy looking but not dying, and just wont spread.

I also have about the same sized dwarf hairgrass on a lava rock that wont spread either in the same amount of time, and appears to be dying off. Its all brown, even after I cut it down a month ago when it was longer and brown with green underneath.

Whats the problem??? I cant figure it out because the other plants are growing so well but the grasses arent???




I have 2 power compact lights (2x65watt each) on either end of the tank, and the grasses are directly under them. I run them for 10 hours a day and use seachem flourish

 

[sampster5000]

I'm not an expert but it might sound like your plants are starving. You might want to start dosing some macro nutrients like nitrogen, phosphorus, and potassium. If you dont want to somehow inject CO2 into the tank you can use seachems excel. Having a lot of light and only light wont make plants grow.

 

[BigJim]

+1 Ferts might help. You may also not have enough light. 130W of light may seem like a lot, but on a 125g, it's really not.

 

[mudraker]

Big Jim and Sampster are both right. Stargrass and DHG are medium to high light plants. You will need at minimum 2WPG and ferts to grown them.

You can increase light and start dosing or invest in lower light plants such as Java Fern, crypts, Bacoba and anubius. Even then, you may need a tad more light and micro nutrient ferts.

 

[FishEggs]

What is your substrate?
it sounds to me like you dont have enough light to support the star and dwarf hair grass. the apongentons do get really big in low light. it seems they stretch for it and can survive in the lower light because of that. the apongeton was my first plant b4 i knew much about lighting and everything else kept dying out but it seemed to thrive. now i have it in a medium lighted tank and it stays small while the other plants thrive. Also what spectrum are your bulbs. they need to be a daylight or plant grow bulb otherwise your plants are getting even less usable light.

How often do you do water changes? not only do you need to do pwc for the fish but the plants need it too.

 

[Buc_Nasty]

hm I never wouldve thought it was light because those two power compacts are such beasts and its so bright. They have to be on top of the glass lids and an inch above (about 25 inches above the actual grass) because of evaporation issues and I know that blocks UVB...do most people have lights without glass between in planted tanks?

Theyre 6700K bulbs
Sand substrate - high desert play sand from home depot
I had been using only florapride for a few months, started using seachem flourish (not the excel) a few days ago...what should I be using ideally? Ive read a million different forums and every one says something different.

I was thinking of trying to sell the power compacts and get T5's because theyre so much more efficient...how many T5s do you guys think I would need?

 

[sampster5000]

What is the size of the tank? Like I said... you might have enough light but you are not injecting CO2 or ferts. Plants cant grow and thrive on light alone.

 

[Buc_Nasty]

its a 125 gallon

 

[JohnPaul]

130W of light over a 125g tank is very, very low light. Basically 1 watt per gallon (WPG). I doubt you'll grow stargrass, and I don't think there's any remote chance that you'll grow hairgrass, in a tank with only 1 WPG of light. I have a small tank (10g) that has 3 WPG (though its spiral CF, so probably more like 2.0 - 2.5 WPG effectively) and stargrass struggles to grow there.

If you want to grow something like hairgrass, you need high light (probably 2.5 WPG or more), CO2 injection, and regular ferts. Anything less than that I would be shocked if you got the results you wanted. Hairgrass is basically a groundcover type of plant and those tend to be among the most demanding of all aquarium plants to grow.

Certainly adding CO2 and a regular fert regime will go a long way towards helping your growth, but my gut tells me you are probably going to have to increase the light as well. But I'm still a relative newbie when it comes to planted tanks so I'll defer to some of the real experts here if they think differently.

 

[DragonFish71]

Stargrass doesn't spread like other plants, it just grows upwards.

I have it growing in a few of our tanks under different conditions and I have to trim once a month. None of the tanks that have it get a fert regime, they get dosed when I remember (yeah I know, sad), none of the tanks have CO2 and the lighting isn't high to medium. The bulbs are just generic bulbs I get at Walmart in the lighting section, nothing fancy.

The 20g long has a 24 inch 6500k daylight bulb, I think it's an 18w.
The 115g has 3 40 inch, 6500k daylight bulbs that are 40w


Now hairgrass I had nothing but problems with even in our high(er) light, CO2, dosing ferts tank.

 

[Buc_Nasty]

I've been doing a lot of research about lighting figured I'd share it summarized here. Found these really good articles.

T5HO Light Intensity

PAR vs Distance, T5, T12, PC

Watts per gallon is essentially useless to even mention. These T5's provide so many more lumens per watt its irrelevant. Plus shorter bulbs need less watts than longer bulbs but provide the same light output. Aka a 48 inch T5 HO uses 54watts, while a 24 inch uses 24 watts, both producing the same amount of light just over a different areas. Watts arent like liters of plant food or something than spreads out through the water. Using my 24 inch 24 watts at either end of the tank doesnt even mean i have 48 "watts per gallon" evenly distributed thru every gallon...the middle of my tank has no light on it (and no plants are there)

The power compacts are not all theyre cracked up to be because their shape and reflectors in the fixtures are so inefficient that a lot of the light is reflected back into themselves and lost. They also are basically T5's but bent in half which leads to a whole lot more light being reflected or aimed directly back into themselves. They also take a lot more wattage. The T5 fixtures with individual reflectors for each bulb are a lot more efficient. It also allows them to penetrate a lot deeper in the tank. I had found another article with more data about lumens per watt but cant find it again now.

I also had a problem where if i put the PC directly on the glass aquarium lid, so much water would condense on the lid then heat up that the lid would crack so the light had to be at least 2 inches above it. The T5's dont give off NEARLY as much heat.

The 24 inch power compacts I have were $140 each with bulbs included at big als. The 24 inch T5's were $70 each plus $16 per bulb

Plus the 2 power compacts I had would cost $110 per year just in electricity while the T5HO will cost only $40. They'll pay themselves off compared to the PC in a year and a half. Plus the T5 bulbs last up to 2 years and cost 16$, while PC last 6-12 months and cost at least 25$. U could also fit a whole lot more T5's above the tank for more light...up to 8. 2 Double power compacts (4 bulbs) would be tough to fit above my 125 gallon.

Overall T5's have way lower initial and operating cost, lower heat, and way more light output being directed at the plants. I just ordered two 24inch 2x24w T5HO fixtures (current nova extreme) from big als. Hopefully i can sell the power compacts. Use "cabinsave10" on orders over $100 and u get free shipping and 10% off. Super cheap.


As far as the plants I'm going to start dosing with excel and a few other nutriets as opposed to just flourish haha.