Rusty steel tank as a pond

[PhilKo]

I recently bought an old 1000 gallon water tank, cut the top 1/4 off, and made it into a pond.

I now have an issue with high PH, I am imagining because of the rust.

My question is, will this go away as biological matter grows on the sides, or do I need to line the inside.

If I have to line it know that there are baffles on the inside so laying a plastic liner inside won't work well, I will need to seal it with some kind of paint. Any ideas or recommendations for something less expensive than the two-part paints I am seeing?

Thanks,
Phil

 

[PhilKo]

 

[GBBUDD]

I have seen many an old tank holding water with life in it i would imagine its a matter of time finding what can tollerate or thrive in that environment.

FLEX seal has a paint and a paste

 

[PhilKo]

I have seen many an old tank holding water with life in it i would imagine its a matter of time finding what can tollerate or thrive in that environment.

FLEX seal has a paint and a paste

Thank you GBBUDD!

 

[addy1]

Welcome to our forum!

Neat looking tank

 

[WaterGardener]

What is your pH? What do your consider high?

 

[j.w]

@PhilKo

 

[PhilKo]

Thank you all for the welcomes and help! What a great group!I
I bought a Pond Master test kit and the PH was 9.0 and the color was darker even than the color reference. I added ten gallons of vinegar which brought it to 7. Two weeks later, back to 9. Two more gallons of vinegar to bring it closer to 7.5. I am not adding water and have about 50 small goldfish in there.
Is it not related to the bare steel and rust?

I am inclined to let it sit and see what happens, but will my biofilter ever work with such a high PH?

 

[Mmathis]

Hello and welcome!

Wow, that one huge tank! I wish I had more knowledge of chemistry, to be helpful. Are there any sharp edges inside?

 

[PhilKo]

Mmathis, Nothing anything could get cut on by grazing it.
It had to have been hand made in the early 1900s, obviously hand bent and welded.

 

[WaterGardener]

I would leave the pH alone. The fish will adjust. The important part of pH is to keep it stable, not having a particular number. If you keep dropping it with vinegar it's just going to bounce back up and that is going to stress the fish, leaving them susceptible to diseases and other issues.

Is the tank rough inside? If so, I would be concerned that the fish might flash against it, causing them some serious damage. If I were in your position, I would use a liner inside or paint it with a sealer to smooth it out.

 

[Mmathis]

@WaterGardener OP said nothing inside sharp.

 

[WaterGardener]

I realize that, but rust can be rough. It could be abrasive enough to remove scales or scrape a fish if it flashed against it.

 

[poconojoe]

I think all that rust is bad news.

If you are that intent on using that tank, this is what I would do... Use a cut-off wheel on a grinder or a sawzall to remove those baffles. Grind down the remaining burrs.

Add something like carpet or foam insulation as a cushion. Then drop in underlayment and an EPDM liner.

Now your fish are in a fish friendly environment and have much more room to swim around. You owe it to the fish to provide a healthy environment. Sorry to say this, but I think that rust is horrible to put it bluntly.

 

[PhilKo]

Poconojoe,
Thank you
I have to keep the baffles or the sides will bow out from the weight of the water. So any liner in this tank just wont work, I will have to paint a pond liner on $$$

Thanks again everyone!