What am I doing wrong? (A long read but I need help bad.)

I can't get dwarf hair grass to grow. I can't get anything to form a carpet which is really my goal but this time I wanted to give it a full effort with something easy to increase my chance of success. This is the second time I've planted a ton of DHG only to have it all whither away. So I keep thinking I must be overlooking something obvious, or I must be making some major fundamental mistake to have such consistent horrible results. Thus, I hate to even ask the question here 'cause I feel like I've read all the usual answers already but I'm desperate now and I need someone to tell me why I'm failing so miserably.

My aquarium: It's a 110gal tall (48"x18"x30"high) I have a concrete background that takes up a lot of space and I keep the water level a few inches low so the total system water volume is about 80gal.

Lighting: I'm using a nova fixture (crappy / no reflectors) with two T5HO bulbs (a plant grow bulb & a 10,000k bulb) fixture sits right on top of the aquarium.

Substrate: Seachem black flourite sand, 2-3" deep

Filtration: Closed loop canister style. It's a major (high quality) DIY job with about 15gpm of flow or 11-12 turn-overs per hour. I don't do water changes per-se. I have a constant-drip system that flows carbon-filtered tap water into the aquarium at about 40gal / week. The aquarium has an overflow plumbed to a drain.

Water temp: is kept at 81*F and far as I can tell stays there very consistently. (+- .5*F)

Ferts: I've been testing the macro-nutrient levels directly with a spectrophotometer and they have never been limiting. If anything they've been on the high side, especially the nitrates. I dose micros (CSM+B) when the iron residual tests low.

CO2: I'm at the max that my fish can take and I have reasonable confidence based on my pH meter that the CO2 level is steady & consistent at that level for the entire 10hr photo period. I say that because I've kept a close eye on the pH reading all day most days and the pH fluctuates between 6.47-6.55. Any lower then 6.50 and my fish reliably show clear signs of stress. CO2 is turned off when the lights go out & back on several hours before the lights come on.

I also dose twice the recommended daily amount of Excel. In the past I've also dosed twice the recommended daily amount of Florin Axis (a non-glutaraldehyde carbon supplement) I've been out of Axis for several weeks though.

Algae: It's on the rocks & glass but not on the DHG. I can tell that I'm very close to the proper CO2 threshold when the algae (bba & green dust) starts going away after a few days or so but if I forget to dose excel for a day or two the algae comes right back. The long-term average is that algae is growing though. It's not going away. Again, it's not on the DHG.

Livestock: A blue peacock cichlid, a few mollys, a couple silver dollars, a big ghost knife, a guppy, a few gouramis, and a couple severums. I'm aware that the fish do pick at any & all plants I've tried to grow it's not usually severe enough to prevent a healthy plant's growth. In this specific case I'm confident that if the DHG would just grow it would easily out-pace the fish.

Plants: After a bunch of failed half-assed attempts to get a carpet plant growing I got tired of my non-scaped mish-mesh of plants & ripped everything out. I decided to just focus on a carpet & then come back for the other plants later. I bought a very nice five square inches of DHG (parvula) from another forum member, separated it into 2-3 plantlet bunches and was able to cover most of the substrate in my aquarium with plantlets spaced about every half inch in more or less a grid pattern. After a couple weeks I noticed the original blades of grass dieing off and new ones very slowly taking their place but the net-growth has been negative over the last month and a half. Of the original plantings there are maybe 25% still showing signs of life. Much of the substrate that had been planted with DHG is now completely bare.

Known Challenges: I have a very tall tank (30") and I don't have a PAR meter. So I can't be certain about my light level at the substrate. From what I've been able to find here & on other forums I'm somewhere in the "medium light" range but it will always be a difficult balance to find in a tank this tall.


So what the heck am I missing? Any ideas? If I had the money I'd offer to fly Tom out to Baltimore for a couple days to get a set of first hand experienced eyes on my setup but that's not going to happen.

Thanks for taking the time folks.

 

I'm not using Excel to fight algae really because I'm not dosing high enough for that. I'm using Excel (& occasionally Axis) mainly as a carbon source to supplement the apparently inadequate CO2.

I can (but haven't) tested dissolved oxygen levels. What level is ideal? Surface agitation is quite strong IMHO. I've got all 15gpm flowing from a single outlet over the surface of the rock wall (and down into the aquarium. It's a high-volume low intensity flow, so not like a power-jet or anything but the current does create micro air bubbles that get carried all the way down to the substrate and 3/4 the length of the aquarium before most of them rise back to the surface. It's easy to get an idea of what the water flow is doing in the aquarium just by watching the bubbles. On the other hand there is hardly any plant bio-mass in the aquarium now to convert CO2 to O2. I've been half tempted to try injecting pure oxygen in addition to the CO2 just to see if the fish do better with higher CO2 levels. I already have an oxygen tank & regulator for it.

Keep in mind, I'm not measuring CO2 with the pH meter absolutely. I'm only using the pH meter as a relative reference. Ie. to say however much CO2 was in the water yesterday at 6.50pH, the same amount is there today at 6.50ph. The number consistency has been confirmed on numerous occasions by the fish behavior. Specifically, during feeding time if I'm pushing too much CO2 my cichlids act sorta spacey and half conscious like they can't get a good aim on the black-worms in the water. Normally the cichlids are ravenous eaters and have no trouble with getting the worms. (I've never seen gasping at the surface from them though, even when they totally passed out a couple times & needed to be moved to a hospital tank briefly to be revived.)

One note on the pH is that as more CO2 is added to the water the pH drops but at an increasing rate. So that the difference in the amount of CO2 in the water between 7.50 and 7.00 pH is much less then the difference between 6.55 and 6.50. It's entirely possible that 6.50 is an adequate amount of CO2 and 6.55 isn't enough but to do any more consistent then that I'd have to do some serious re-engineering of my very typical CO2 delivery system.

Here's some OLD pictures of my aquarium. (None of the fish or plants in this picture are in the aquarium now)







Here is the filter outlet (pictured above & below.) In this picture there was 6 gpm. There is now 15 gpm, so more then twice as much flow as in this pic. (I upgraded the pump)



Pictured below is the OLD filtration system. The new one has almost three times the capacity for flow, media, etc. I'm still using the same Hydor ETH 300w heater but I upgraded the canisters, the pump, I added a third flow meter (they're run in parallel), improved tap-water drip metering system, and the UV unit (which I'm not currently using because it removes the iron residual) and of course the pressurized CO2 system was added after this pic was taken also.

 

You think I don't have enough light? Seriously? I mean, I've contemplated that idea but when I turn on a third bulb I get somewhat of an algae explosion on the glass (green dust) and on the rock wall (bba everywhere.) Considering I'm already at the max amount of CO2 that I can possibly get into the tank without killing things it sounds like I'm stuck between a rock & a hard place. I thought Tom always advocated a low-light tank anyway? Perhaps I'm in dire need of borrowing or buying a PAR meter to nail that parameter down for sure? I currently run one 10,000k bulb and one plant grow bulb. Would I do better to run just two 10,000k bulbs? (since I already have another 10,000k bulb I could swap in place of the plant grow bulb.)

Removing algae spores in my system seems almost impossible. I'd have to completely drain the tank for that and pump bleach-water through the entire system. Not to mention trying not to lose fish in the process. Is that really a critically necessary move?

Oh, and I forgot to answer Biollante: My fixture holds four T5HO (54w each) bulbs. I've been running only one pair 10hrs / day. I've played with 8 & 9hr /day periods with no noticeable difference really.

 

Mounting reflectors would be a difficult option because my fixture has no room for them. I mean, if it has to be done then that's what I'll do. I'll figure a way or buy a new fixture if I must. It would be easier if I could somehow get the right amount of light from the fixture I have. Even if it means using using too many bulbs but cutting back the light with window screen or some other way of moderating it. That method won't keep the light off the front glass the way you describe though. I guess I'm a little bitter about having bought an expensive (for me) fixture only to have it not work as well as I thought.

As for using Excel on the rocks to kill the algae... I've got a lot of surface area to cover. 20ml diluted to 50% = 40ml = a full shot glass. I guess I could do it that way but it's gonna take a week or so like that without over-dosing.

 

Dutchy,

So what you're saying is that your couple of tests there are a reasonable approximation of the amount of light I'm using and that amount was found to be woefully inadequate. That sound about right?

As frustrating as this light issue is that is very helpful and I thank everyone for their responses so far. Here I was worried that I was bordering on too much light and come to find out I need almost double. That very well could be my problem.

For now, I've turned on a third bulb and cut my photo-period from 10hrs down to 8hrs. When I get time (lord knows when that will be) I'll pick up some reflectors and go about re-engineering my light fixture. That will probably help a great deal I think. I do hear what you guys are saying about increasing light slowly but I've got nothing to lose right now. I'm essentially starting with a bare tank. I'm just gonna make the adjustments all the way & be done with it. There's nothing in there that needs to be acclimated other then a few wisps of DHG. I'm going to have to buy more of that for a fresh start once I get my problems sorted anyway.



Biollante,

I am (not perfect but) very consistent with my excel dosing. You think this could be causing a problematic fluctuation in CO2 levels? I miss a dose maybe once every other week.

Why a massive water change? What's Potassium permanganate? An algaecide?

8mg/l dissolved oxygen- good to know thank you. I'll make a point of testing this in the near future to see where I'm at.

My problems aren't overwhelming per se, but they're beyond my ability to figure out on my own right now and I'm way too invested in this hobby (in terms of money, time, and enjoyment) to be failing so miserably. I am supremely frustrated at this point so I appreciate you guys taking the time for me.

 

Thanks for the reply Gerry. My responses in blue:

 

UPDATE:

Got my hands on an Apogee PAR meter. (Actually, I just broke down & bought one.)

I tested the amount of light that I had been using while having problems and got about 30 micromols. You guys still think that's not enough light to grow plants?

After I cleaned the plexi-glass cover on my light fixture I gained 5 micromols. Then I tested the 10kk and plant grow bulbs individually. They only differ by about 2 micromols. Each single bulb in my setup gives about 20 micromols at the substrate so just by removing bulbs from the fixture my four choices are: 20, 40, 57, and 75 micromols. You guys have any preference for one of those numbers?

 

So what is better: 57 or 75 micromols? Would 75 be too much / high-light?