Jumpstarting an old reef tank

[ironcity]

Hello. I’m new to this site, not so new to reef aquariums. I have a 37 gallon reef tank. It has been going for almost 19 years now. I have a live sand bottom and live rock. I’ve never kept more than 3” of fish. It flourished for quite a while. It has a simple floss and carbon filter and a bio wheel. I have not run the skimmer in over a decade. And I haven’t kept up with the tank for about 5 years. It’s been 3 since a partial water change. Have not had fish for about 5 years. It still has a couple snails, hermits, and tons of copepods living in it. Brain is my last surviving coral , but it is barely hanging in there. Also some sponges still living. It grew some kind of sturdy, leafy algae and what I believe dinoflagellate (spelling). I want to get it really cleaned up and running again. My issue I want any thoughts on are my water parameters.
Ph: 8.1
Ammonia: 0
Nitrite: 0
Nitrate: 0
dKh: something higher than 8.5
Mg: 1425
Ca: 475
PO4: 0
SG: 1.0245
Temp: Always 82
I read Dino thrives in water devoid of PO4. And I read my Mg, Ca, and Kh are too high, while my Ph is too low.
I’m thinking a partial water change while sucking up the dino. Starting up my skimmer again to help ensure the oxygen is up and CO2 is down to maybe help the Ph. And then adding a couple inches of fish so the biomass adds to PO4 and nitrates. I was surprised at having a low Ph with high KhMg, and Ca.
It is a small tank with no Refugium and minimal space.
Any thoughts are appreciated, especially regarding the water parameters and my thoughts on normalizing the parameters

 

[Reef_at_Sea]

Do you measure any phosphates?
If all of your nutrients have been 0 for quite a while then there might be a chance that a lot of beneficial bacteria are gone.

 

[Subsea]

Hello. I’m new to this site, not so new to reef aquariums. I have a 37 gallon reef tank. It has been going for almost 19 years now. I have a live sand bottom and live rock. I’ve never kept more than 3” of fish. It flourished for quite a while. It has a simple floss and carbon filter and a bio wheel. I have not run the skimmer in over a decade. And I haven’t kept up with the tank for about 5 years. It’s been 3 since a partial water change. Have not had fish for about 5 years. It still has a couple snails, hermits, and tons of copepods living in it. Brain is my last surviving coral , but it is barely hanging in there. Also some sponges still living. It grew some kind of sturdy, leafy algae and what I believe dinoflagellate (spelling). I want to get it really cleaned up and running again. My issue I want any thoughts on are my water parameters.
Ph: 8.1
Ammonia: 0
Nitrite: 0
Nitrate: 0
dKh: something higher than 8.5
Mg: 1425
Ca: 475
PO4: 0
SG: 1.0245
Temp: Always 82
I read Dino thrives in water devoid of PO4. And I read my Mg, Ca, and Kh are too high, while my Ph is too low.
I’m thinking a partial water change while sucking up the dino. Starting up my skimmer again to help ensure the oxygen is up and CO2 is down to maybe help the Ph. And then adding a couple inches of fish so the biomass adds to PO4 and nitrates. I was surprised at having a low Ph with high KhMg, and Ca.
It is a small tank with no Refugium and minimal space.
Any thoughts are appreciated, especially regarding the water parameters and my thoughts on normalizing the parameters

First off: 8.1 is not low pH. AND your alkalinity & calcium are good to go and not high. However, if you try to raise pH, you may get a snowstorm of precipitation.

Get some snails & hermits and start feeding your tank. Consider getting a diver collected live rock to bring in biodiversity.

P.S. with so few fish, I see little point in the bio wheel.

 

[ironcity]

Do you measure any phosphates?
If all of your nutrients have been 0 for quite a while then there might be a chance that a lot of beneficial bacteria are gone.

Yes, the phosphates are at zero. I have not thought about beneficial bacteria possibly being low. Any suggestions? Maybe just getting fish back into the tank would help.

 

[ironcity]

First off: 8.1 is not low pH. AND your alkalinity & calcium are good to go and not high. However, if you try to raise pH, you may get a snowstorm of precipitation.

Get some snails & hermits and start feeding your tank. Consider getting a diver collected live rock to bring in biodiversity.

P.S. with so few fish, I see little point in the bio wheel.

Thank you for the reply. I feel better about the Ca and Mg since you feel they are not high. And that you feel 8.1 isn’t low. I did not know raising Ph could cause a mineral precipitation issue.

I will get snails and crabs. When you say to start feeding the tank, do you mean dropping food pellets for the crabs?

 

[Subsea]

When you maximize both pH & alkalinity, you reach the solubility limit of calcium and a mineral precipitation snowstorm can results. However, before that happens, limescale of calcium carbonate will coat any warm surface like a pump or a heater.

PS: consider soft corals who like high nutrient systems which, in my experiences, are more forgiving.

 

[Reef_at_Sea]

Yes, the phosphates are at zero. I have not thought about beneficial bacteria possibly being low. Any suggestions? Maybe just getting fish back into the tank would help.

I would just start with dosing ammonia & monitor how fast it drops.
Should be 2ppm to 0ppm in 24 hours

 

[JumboShrimp]

Post a photo of your tank when you get a chance-- we love photos! :)

 

[ironcity]

I would just start with dosing ammonia & monitor how fast it drops.
Should be 2ppm to 0ppm in 24 hours

I have not heard of dosing ammonia. What does that do or what does that tell me?

 

[Reef_at_Sea]

I have not heard of dosing ammonia. What does that do or what does that tell me?

Dosing ammonia is pretty much the same as adding a raw shrimp or mussel.
It starts "rotting" causing ammonia wich the beneficial bacteria turn into nitrites and then nitrates.
If you dose ammonia into your reef tank & don't see it being turned into nitrates then i'm pretty sure your beneficial bacteria are gone, wich means that you should start adding new bacteria.
Basically a new cycle.

 

[ironcity]

Dosing ammonia is pretty much the same as adding a raw shrimp or mussel.
It starts "rotting" causing ammonia wich the beneficial bacteria turn into nitrites and then nitrates.
If you dose ammonia into your reef tank & don't see it being turned into nitrates then i'm pretty sure your beneficial bacteria are gone, wich means that you should start adding new bacteria.
Basically a new cycle.

Interesting. Thank you for the idea. I will look into it

 

[Tahoe61]

I am concerned about the 19 yr old sandbed. How deep is it and what media did you use?

 

[rhitee93]

With a tank that size, I think I would take everything out, give the tank a good cleaning, replace the sand with fresh material, scrub the rocks as well as I could and put everything back in with fresh salt water.

 

[ironcity]

I am concerned about the 19 yr old sandbed. How deep is it and what media did you use?

It is black and white Hawaiian live sand. Approximately 3 inches deep. The sand sits directly on the aquarium glass floor. The live rock sits on top of the sand

 

[Subsea]

Thank you for the reply. I feel better about the Ca and Mg since you feel they are not high. And that you feel 8.1 isn’t low. I did not know raising Ph could cause a mineral precipitation issue.

I will get snails and crabs. When you say to start feeding the tank, do you mean dropping food pellets for the crabs?

You must get your nitrates & phosphates up. Either feed fish or add nitrogen & trace minerals. I dose ammonia & liquid kelp concentrate. If you do large water changes, you will introduce trace minerals.

Not sure I would add crabs. I like snails and small blue leg hermits.

Please take a full tank picture with white light.

 

[ironcity]

Without knowing previous history, after 19 years, I feel the same way except I would probably reuse the sand after flushing & sanitizing with municipal water. However I would add a small amount of diver collected live sand and some diver collected uncured live rock to bring in micro fauna & fana.

https://gulfliverock.com/premium-deco-live-rock
https://gulfliverock.com/hitchhiker-id

Without knowing previous history, after 19 years, I feel the same way except I would probably reuse the sand after flushing & sanitizing with municipal water. However I would add a small amount of diver collected live sand and some diver collected uncured live rock to bring in micro fauna & fana.

https://gulfliverock.com/premium-deco-live-rock
https://gulfliverock.com/hitchhiker-id

Thank you for all of the ideas. Out of curiosity, why clean or replace the sand. I didn’t know an old bed was bad. Here is a picture of the tank.

 

[Subsea]

Thank you for all of the ideas. Out of curiosity, why clean or replace the sand. I didn’t know an old bed was bad. Here is a picture of the tank.

Thank you for all of the ideas. Out of curiosity, why clean or replace the sand. I didn’t know an old bed was bad. Here is a picture of the tank.

A consensus of many and the assumption is that a sandbed is a nutrient sink that will eventually regurgitate its accumulation of organics.

I use my sand bed to recycle nutrients thru multiple nutrient pathways that feed the microbial food web.

Your sandbed looks fine. Unless you are attached to seeing that macro algae, I would remove it. Then add biodiversity with diver collected live sand & diver collected live rock. Both Tampa Bay Saltwater & Gulf Live Rock are an excellent source.

Provide extra circulation or air bubblers when introducing sand & rock. Consider more circulation. Please describe your lights for growing coral.

After system has stabilized, add fish and feed abundantly. Fish poop is excellent coral nutrition.