OK, I screwed up. Now what?

[Mark F]

I apologize in advance for the long post, but I want everyone to get a full picture of my situation.

I've had my FOWLR 40G tank setup for almost 2 years now, and have been using "the force" to decide when to change water, which hasn't been regularly to say the least. I had no problems whatsoever with this method until about 2 months ago when I had a bad hair algae outbreak that has stayed with me no matter what.

Here's my tank parameters:

40G FOWLR tank (about 30lb LR)
3" crushed coral substrate
1 clownfish
1 royal dottyback
1 lemonpeel angelfish
1 black and white damsel
About 10 misc. hermits
About 10 misc. snails
1 colony of xenia
1 colony of mushrooms

2 MJ1200 for water circulation
Knop HOT skimmer with MJ1200 venturi kit alteration

Anyway, my nitrates are the problem as far as I know. They are hovering around 100 even with constant 8G water changes 1-2 times per week. I'm assuming that's what's causing my algae problems. I'm using RO water for all water changes and have been ever since I setup my tank. I've tried adding more hermits and snails and a goby to help keep the tank clean, but most of them died within a few weeks. The weird thing is that the fish and corals that I've had since the beginning seem to be thriving, except for anything new I might try to add.

I'm wondering if I should do something drastic like replace 50% or more of the water. Another idea I've been toying with is replacing a bunch of the water and switching out the substrate for live sand at the same time.

Can anyone offer me some suggestions please? Thanks in advance.

Mark F

[Tadashi]

Do not replace too much water at once. If anything do 25% every couple days.

It seems that those with strictly CC substrates do have battles with nitrates. I have a DSB with LS due to the simplicity and ease in setting it up. I would recommend this.

I am not familiar with your skimmer. What size tank is ir rated for? How is the skimmate that is pulled from it (dark)?

You need to ensure that you are exporting more nutrients than you are adding. How much are you feeding your tank?

[3_high_low]

HI Mark,
Sounds like you're in touch with your system. I think it would be wise to remove all the CC. Maybe first you can take a water sample exclusively from the substrate to confirm it as the NO3 source. I bet the reading would be even higher than the open water sample.

A DSB sounds like a fine idea providing you stay away from sand critter preditorial animals.

Good luck!

[Mark F]

Thanks for the replies so far!

Tadashi-
I don't remember what my skimmer is rated for, but I'm almost positive it's 60-100 gallons. Jason from Premium Aquatics sold it to me (I'm lucky enough to live in the same city) and I know we discussed my tank size. The skimmate it pulls is very dark. I seem to have the same problem with this skimmer that others have mentioned - that after skimming fine for a few days it seems to stop being effective even though the cup is only 1/4 full at most. As long as I empty the cup often enough it skims fine though.
As far as feeding goes, I err on the side of light feeding if anything. I feed only once every 2-3 days, but the fish don't seem to mind.

3_high_low-
You mention taking a water sample from the substrate, but how exactly does one do this?

Also, I'm moving into a new house in about 45 days which will necessitate moving the tank. I was thinking of trying to change out the substrate at that time since I'll be emptying a lot of the water from the tank anyways. I know my wife HATES looking at the algae, but do you think I'd be endangering any of my livestock if I just continue doing regular water changes until then? I doubt I'll have much effect on the nitrates until the substrate change.

Mark F

[OrionN]

If you use aged and airated water with the same salinity and temp, you should not have any problem changeing a large amount of water. I would do an 80% water change and be done with the nitrate in your tank. You need to decrease feeding and make sure you don't add any nitrated in the new water and in the top-off water.

[Callie]

This might work also. Since you will be moving in 45 days, maybe you could set up a tank (large rubbermaid or other "safe" tub would work also) with some aragonite sand and something to cycle it (a piece of shrimp works well). by the time you are ready to move the tank you should have some cycled substrate (why pay for 60lbs live sand?). When you set the tank up again after the move, change out the substrate and add a few lbs of live sand to seed your substrate. You should have only a small spike if any and you won't release all the nasties from the crushed coral substrate.

You could just change the substrate when you move, but without the beneficial bacteria you had in the CC, you will have a much larger spike (cycle) than you would using cycled substrate. The LR will help but probably not enough to avoid another cycle.

I have not done something like that (haven't had to move since I set my tanks up) so I'm not speaking facts, just conjecture, but it makes sense to me and that's how I would do it if I was in your situation.

Maybe someone else has gone through this and can confirm or deny if this would work.

Kathy

[DwayneNelson]

I would guess its the crushed coral substate. A good skimmer, live rock and live sand go a long way at eliminating nitrates. No matter what I feed, my nitrates never go above 1ppm. I have the skimmer, live rock and live sand.

I used to have a fish only tank with CC. I could NEVER get nitrates below 100. I tried everything.

[3_high_low]

Originally posted by Mark F

3_high_low-
You mention taking a water sample from the substrate, but how exactly does one do this?

Mark F

MarkF,
If you have long arms and a towel:) reach in and get a sample, keep the sample vile inverted(full of air) until you reach the substrate then allow it to fill. Or use a piece of airline and siphon some out.

If the animals seem fine up to now perhaps you can ride it out with water exchanges 'til you move.

On the other hand, can you siphon the crushed coral right out of the tank?

[Terra Ferma]

Ditch the CC substrate, I use no subrate now, but have used a DSB and also CC. The CC is a trap for nitrates. The Knop skimmer: if it pulls dark stuff out, it is probably O.K. Knop is a reputable guy, and I do not know his relationship with marketing this skimmer, but perhaps a better skimmer is on your horizon. It should not be very hard to reduce nitrates in this tank, are you sure you test kit is accurate?

[Tadashi]

Since you are moving I would replace the substrate. Get a 22-gal rubbermaid bin and fill with new sand. Use the calculators to figure out how much you need. Then order about 5 lbs of LS and place on top. Place a power head on it and feed it every couple days.

Use our old WC water to fill this rubbermaid bin.

When you move bag everyone up. Move the tank. Scoop top layer of LS out with your hands and place in container (using our hand will be less damaging on the worms). Place the rest of the cured sand in the 40-gal. Then place LS on top again. Slowly fill with water. This should reduce the cloudiness. Once water clears aquascape, test equipment, then add livestock. Use whatever clean water you can from the rubbermaid bin and none of the water from the 40-gal.

It sounds like your skimmer is doing fine just needs help with nutrient recycling (DSB).

I would not worry about measuring the nitrates above the CC.

[Alice]

Scoop top layer of LS out with your hands

Be sure to wear gloves! Bristle worm stings are nasty.

I can't remember where I got the tip but I filled some pieces of nylon stocking with some old substrate to help cycle my 125 when I changed over from my old 55. It worked great, barely got a spike. I used about 8 softball sized substrate "sausages" six in the tank and two in the sump. Left them there for about two weeks. I did use some of the old substrate mixed in with the new but the old was heavy and clumpy and I wanted rid of it.

Good luck with your upcoming move :)

~Alice

[Flamin`Angel]

Hi Ya Mark
Have you actually tested the RO-water you make:confused: The filters inside the unit could be too old.Some SW-pals of mine change cartridge every year,just to be safe ;)

FWIW

[aLittletank]

Originally posted by Mark F
The weird thing is that the fish and corals that I've had since the beginning seem to be thriving, except for anything new I might try to add.
your current animals have been brought to their current toxic level over a period of time, so they are surviving. make no mistake though there is damage being done to them. the longer they are exsposed the worse the damage. any new animals you try to add cant take the imediate change from normals levels to your tanks levels.

it is said you can boil a frog alive if you raise the temp slowly


I'm wondering if I should do something drastic like replace 50% or more of the water. I would do a 50% change every three days for a couple of weeks. then a 25% every week until you change over to a DSB and get rid of the crushed coral.

Another idea I've been toying with is replacing a bunch of the water and switching out the substrate for live sand at the same time.
great idea! get the small grain sand though


[/B]

Allen

[albe1947]

Mark. Not to knock the other members, but you said the tank is setup for 2 years without any problems, So I figure it's not the crushed coral bed. Where are you getting the ro water, and when were the filters changed?, maybe the water is the source of the problem. It's Ok to do large water change. An 80% is fine if the parameters are correct. I have seen 100% changes when theres a problem with no ill effects. Just make sure the PH and Selinity are very close.

[aLittletank]

Originally posted by albe1947
Mark. Not to knock the other members, but you said the tank is setup for 2 years without any problems, So I figure it's not the crushed coral bed.


thats just it. eventually a crushed coral bed is going to give you the problems with nitrates. the reason it took so long here is probably because the guy is hardly feeding at all. (2-3 times a week)

It is true that an overwhelming percent of RC members will tell you to change to a DSB. mainly because of the research that DR Ron has done on the subject. not that we are a Dr Ron cult or anything!

oh I see it is past 1:30. I must go light a candel upon the ron alter and dance the DSB ritual dance. :D


Allen

[Marty M]

Mark, if the crushed coral is causing the high nitrates then it must also be a significant part of your bio filtration. I wouldn't get rid of it too quickly or you might get an ammonia spike. I would do a series of water changes before the move, and use the waste water to thoroughly rinse a portion of the bed each time. I liked the cc sausage idea. Put the rinsed cc in nylon bags and put it back in the tank until the whole bed is packed, but still functioning. When you move, install the new sand bed, then place the cc packs on top of it. If you remove one cc pack at a time, over several weeks, you shouldn't have an ammonia problem. Just to be safe, you should pick up an ammonia monitor by Seachem. It stays in the tank so you can detect ammonia buildup at a glance. I don't think you can successfully acclimate any new animals until the nitrates are under control, in the 10-20 range.

[Mark F]

Thanks for the advice so far. Well, I think I'm definitely going to take the plunge with a DSB, I just haven't decided if I will wait until we move or not. I may go ahead and just start the process this coming weekend. The nylon suggestion seems like a good one as does the ammonia monitor, so my thanks to Alice and Marty.

To those of you inquiring about my RO water, I actually thought of that myself this weekend, but haven't tested the source water yet. I plan to tonight. I don't have my own RO unit, so I buy RO water at the grocery store for $0.35/gallon. I have always assumed it to be the same quality as what I could make with an RO unit, but I suppose I need to test to be sure. I guess an RO unit is one more thing I should put on my birthday list! :)

Mark